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  <title>CSS Images Module Level 3</title>
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  <meta content="This module contains the features of CSS level 3 relating to the <image> type and some replaced elements.  	It includes and extends the functionality of CSS level 2 [[CSS2]].  	The main extensions compared to CSS2.1 are the generalization of the <url> type to the <image> type,  	several additions to the <image> type, a generic sizing algorithm for images and other replaced content in CSS,  	definitions for interpolating several <image> types,  	and several properties controlling the interaction of replaced elements and CSS&apos;s layout models." name="abstract">
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 <body class="h-entry">
  <div class="head">
   <p data-fill-with="logo"><a class="logo" href="https://www.w3.org/"> <img alt="W3C" height="48" src="https://www.w3.org/StyleSheets/TR/2016/logos/W3C" width="72"> </a> </p>
   <h1 class="p-name no-ref" id="title">CSS Images Module Level 3</h1>
   <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Editor’s Draft, <time class="dt-updated" datetime="1970-01-01">1 January 1970</time></span></h2>
   <details>
    <summary>Specification Metadata</summary>
    <div data-fill-with="spec-metadata">
     <dl>
      <dt>This version:
      <dd><a class="u-url" href="https://drafts.csswg.org/css-images-3/">https://drafts.csswg.org/css-images-3/</a>
      <dt>Latest published version:
      <dd><a href="https://www.w3.org/TR/css3-images/">https://www.w3.org/TR/css3-images/</a>
      <dt>Previous Versions:
      <dd><a href="https://www.w3.org/TR/2012/CR-css3-images-20120417/" rel="prev">https://www.w3.org/TR/2012/CR-css3-images-20120417/</a>
      <dd><a href="https://www.w3.org/TR/2012/WD-css3-images-20120112/" rel="prev">https://www.w3.org/TR/2012/WD-css3-images-20120112/</a>
      <dt>Test Suite:
      <dd><a href="http://test.csswg.org/suites/css-images-3_dev/nightly-unstable/">http://test.csswg.org/suites/css-images-3_dev/nightly-unstable/</a>
      <dt>Issue Tracking:
      <dd><a href="http://www.w3.org/Style/CSS/Tracker/products/27">Tracker</a>
      <dd><a href="https://github.com/w3c/csswg-drafts/labels/css-images-3">GitHub Issues</a>
      <dt class="editor">Editors:
      <dd class="editor p-author h-card vcard" data-editor-id="42199"><a class="p-name fn u-url url" href="http://xanthir.com/contact/">Tab Atkins Jr.</a> (<span class="p-org org">Google</span>)
      <dd class="editor p-author h-card vcard" data-editor-id="35400"><a class="p-name fn u-url url" href="http://fantasai.inkedblade.net/contact">Elika J. Etemad / fantasai</a> (<span class="p-org org">Invited Expert</span>)
      <dd class="editor p-author h-card vcard" data-editor-id="52258"><a class="p-name fn u-url url" href="http://lea.verou.me/about">Lea Verou</a> (<span class="p-org org">Invited Expert</span>)
      <dt>Suggest an Edit for this Spec:
      <dd><a href="https://github.com/w3c/csswg-drafts/blob/master/css-images-3/Overview.bs">GitHub Editor</a>
     </dl>
    </div>
   </details>
   <div data-fill-with="warning"></div>
   <p class="copyright" data-fill-with="copyright"><a href="https://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 1970 <a href="https://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a href="https://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>, <a href="https://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>, <a href="https://www.keio.ac.jp/">Keio</a>, <a href="https://ev.buaa.edu.cn/">Beihang</a>). W3C <a href="https://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="https://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="https://www.w3.org/Consortium/Legal/2015/copyright-software-and-document">permissive document license</a> rules apply. </p>
   <hr title="Separator for header">
  </div>
  <div class="p-summary" data-fill-with="abstract">
   <h2 class="no-num no-toc no-ref heading settled" id="abstract"><span class="content">Abstract</span></h2>
   <p>This module contains the features of CSS level 3 relating to the <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image">&lt;image></a> type and some replaced elements.

	It includes and extends the functionality of CSS level 2 <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a>.
	The main extensions compared to CSS2.1 are the generalization of the <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#url-value" id="ref-for-url-value">&lt;url></a> type to the <span class="production" id="ref-for-typedef-image①">&lt;image></span> type,
	several additions to the <span class="production" id="ref-for-typedef-image②">&lt;image></span> type, a generic sizing algorithm for images and other replaced content in CSS,
	definitions for interpolating several <span class="production" id="ref-for-typedef-image③">&lt;image></span> types,
	and several properties controlling the interaction of replaced elements and CSS’s layout models.</p>
    <a href="https://www.w3.org/TR/CSS/">CSS</a> is a language for describing the rendering of structured documents
(such as HTML and XML)
on screen, on paper, etc. 
  </div>
  <h2 class="no-num no-toc no-ref heading settled" id="status"><span class="content">Status of this document</span></h2>
  <div data-fill-with="status">
   <p> This is a public copy of the editors’ draft.
	It is provided for discussion only and may change at any moment.
	Its publication here does not imply endorsement of its contents by W3C.
	Don’t cite this document other than as work in progress. </p>
   <p> <a href="https://github.com/w3c/csswg-drafts/issues">GitHub Issues</a> are preferred for discussion of this specification.
	When filing an issue, please put the text “css-images” in the title,
	preferably like this:
	“[css-images] <i data-lt>…summary of comment…</i>”.
	All issues and comments are <a href="https://lists.w3.org/Archives/Public/public-css-archive/">archived</a>,
	and there is also a <a href="https://lists.w3.org/Archives/Public/www-style/">historical archive</a>. </p>
   <p> This document was produced by the <a href="https://www.w3.org/Style/CSS/">CSS Working Group</a>. </p>
   <p> This document was produced by a group operating under
	the <a href="https://www.w3.org/Consortium/Patent-Policy/">W3C Patent Policy</a>.
	W3C maintains a <a href="https://www.w3.org/2004/01/pp-impl/32061/status" rel="disclosure">public list of any patent disclosures</a> made in connection with the deliverables of the group;
	that page also includes instructions for disclosing a patent.
	An individual who has actual knowledge of a patent which the individual believes contains <a href="https://www.w3.org/Consortium/Patent-Policy/#def-essential">Essential Claim(s)</a> must disclose the information in accordance with <a href="https://www.w3.org/Consortium/Patent-Policy/#sec-Disclosure">section 6 of the W3C Patent Policy</a>. </p>
   <p> This document is governed by the <a href="https://www.w3.org/2019/Process-20190301/" id="w3c_process_revision">1 March 2019 W3C Process Document</a>. </p>
   <p></p>
  </div>
  <div data-fill-with="at-risk">
   <p>The following features are at-risk, and may be dropped during the CR period: </p>
   <ul>
    <li><a class="property" data-link-type="propdesc" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation">image-orientation</a>
   </ul>
   <p>“At-risk” is a W3C Process term-of-art, and does not necessarily imply that the feature is in danger of being dropped or delayed. It means that the WG believes the feature may have difficulty being interoperably implemented in a timely manner, and marking it as such allows the WG to drop the feature if necessary when transitioning to the Proposed Rec stage, without having to publish a new Candidate Rec without the feature first.</p>
  </div>
  <nav data-fill-with="table-of-contents" id="toc">
   <h2 class="no-num no-toc no-ref" id="contents">Table of Contents</h2>
   <ol class="toc" role="directory">
    <li>
     <a href="#intro"><span class="secno">1</span> <span class="content">Introduction</span></a>
     <ol class="toc">
      <li><a href="#placement"><span class="secno">1.1</span> <span class="content">Module Interactions</span></a>
      <li><a href="#values"><span class="secno">1.2</span> <span class="content">Values</span></a>
     </ol>
    <li>
     <a href="#image-values"><span class="secno">2</span> <span class="content">Image Values: the <span class="production">&lt;image></span> type</span></a>
     <ol class="toc">
      <li>
       <a href="#url-notation"><span class="secno">2.1</span> <span class="content">Image References: the <span class="css">url()</span> notation</span></a>
       <ol class="toc">
        <li><a href="#ambiguous-urls"><span class="secno">2.1.1</span> <span class="content">Ambiguous Reference-or-Image URLs</span></a>
       </ol>
     </ol>
    <li>
     <a href="#gradients"><span class="secno">3</span> <span class="content">Gradients</span></a>
     <ol class="toc">
      <li><a href="#linear-gradients"><span class="secno">3.1</span> <span class="content">Linear Gradients: the <span class="css">linear-gradient()</span> notation</span></a>
      <li><a href="#radial-gradients"><span class="secno">3.2</span> <span class="content">Radial Gradients: the <span class="css">radial-gradient()</span> notation</span></a>
      <li><a href="#repeating-gradients"><span class="secno">3.3</span> <span class="content">Repeating Gradients: the <span class="css">repeating-linear-gradient()</span> and <span class="css">repeating-radial-gradient()</span> notations</span></a>
      <li>
       <a href="#gradient-colors"><span class="secno">3.4</span> <span class="content">Defining Gradient Color</span></a>
       <ol class="toc">
        <li><a href="#color-stop-syntax"><span class="secno">3.4.1</span> <span class="content"> Color Stop Lists</span></a>
        <li><a href="#coloring-gradient-line"><span class="secno">3.4.2</span> <span class="content"> Coloring the Gradient Line</span></a>
        <li><a href="#color-stop-fixup"><span class="secno">3.4.3</span> <span class="content"> Color Stop “Fixup”</span></a>
       </ol>
     </ol>
    <li>
     <a href="#sizing"><span class="secno">4</span> <span class="content">Sizing Images and Objects in CSS</span></a>
     <ol class="toc">
      <li><a href="#sizing-terms"><span class="secno">4.1</span> <span class="content">Object-Sizing Terminology</span></a>
      <li><a href="#object-negotiation"><span class="secno">4.2</span> <span class="content">CSS⇋Object Negotiation</span></a>
      <li>
       <a href="#concrete-size-resolution"><span class="secno">4.3</span> <span class="content">Concrete Object Size Resolution</span></a>
       <ol class="toc">
        <li><a href="#default-sizing"><span class="secno">4.3.1</span> <span class="content">Default Sizing Algorithm</span></a>
        <li><a href="#cover-contain"><span class="secno">4.3.2</span> <span class="content">Cover and Contain Constraint Sizing</span></a>
       </ol>
      <li><a href="#object-sizing-examples"><span class="secno">4.4</span> <span class="content">Examples of CSS Object Sizing</span></a>
      <li><a href="#the-object-fit"><span class="secno">4.5</span> <span class="content">Sizing Objects: the <span class="property">object-fit</span> property</span></a>
      <li><a href="#the-object-position"><span class="secno">4.6</span> <span class="content">Positioning Objects: the <span class="property">object-position</span> property</span></a>
     </ol>
    <li>
     <a href="#image-processing"><span class="secno">5</span> <span class="content">Image Processing</span></a>
     <ol class="toc">
      <li><a href="#the-image-orientation"><span class="secno">5.1</span> <span class="content">Orienting an Image on the Page: the <span class="property">image-orientation</span> property </span></a>
      <li><a href="#the-image-rendering"><span class="secno">5.2</span> <span class="content">Determining How To Scale an Image: the <span class="property">image-rendering</span> property</span></a>
     </ol>
    <li><a href="#interpolation"><span class="secno">6</span> <span class="content">Interpolation</span></a>
    <li><a href="#serialization"><span class="secno">7</span> <span class="content">Serialization</span></a>
    <li><a href="#privsec"><span class="secno"></span> <span class="content"> Privacy and Security Considerations</span></a>
    <li><a href="#acknowledgments"><span class="secno"></span> <span class="content"> Acknowledgments</span></a>
    <li>
     <a href="#changes"><span class="secno"></span> <span class="content"> Changes</span></a>
     <ol class="toc">
      <li><a href="#changes-20120407"><span class="secno"></span> <span class="content"> Changes Since the <span>17 April 2012 Candidate Recommendation</span></span></a>
      <li><a href="#changes-last-call"><span class="secno"></span> <span class="content"> Changes Since Last Call</span></a>
     </ol>
    <li>
     <a href="#conformance"><span class="secno"></span> <span class="content"> Conformance</span></a>
     <ol class="toc">
      <li><a href="#document-conventions"><span class="secno"></span> <span class="content"> Document conventions</span></a>
      <li><a href="#conform-classes"><span class="secno"></span> <span class="content"> Conformance classes</span></a>
      <li>
       <a href="#conform-responsible"><span class="secno"></span> <span class="content"> Requirements for Responsible Implementation of CSS</span></a>
       <ol class="toc">
        <li><a href="#conform-partial"><span class="secno"></span> <span class="content"> Partial Implementations</span></a>
        <li><a href="#conform-future-proofing"><span class="secno"></span> <span class="content"> Implementations of Unstable and Proprietary Features</span></a>
        <li><a href="#conform-testing"><span class="secno"></span> <span class="content"> Implementations of CR-level Features</span></a>
       </ol>
     </ol>
    <li>
     <a href="#index"><span class="secno"></span> <span class="content">Index</span></a>
     <ol class="toc">
      <li><a href="#index-defined-here"><span class="secno"></span> <span class="content">Terms defined by this specification</span></a>
      <li><a href="#index-defined-elsewhere"><span class="secno"></span> <span class="content">Terms defined by reference</span></a>
     </ol>
    <li>
     <a href="#references"><span class="secno"></span> <span class="content">References</span></a>
     <ol class="toc">
      <li><a href="#normative"><span class="secno"></span> <span class="content">Normative References</span></a>
      <li><a href="#informative"><span class="secno"></span> <span class="content">Informative References</span></a>
     </ol>
    <li><a href="#property-index"><span class="secno"></span> <span class="content">Property Index</span></a>
    <li><a href="#issues-index"><span class="secno"></span> <span class="content">Issues Index</span></a>
   </ol>
  </nav>
  <main>
   <h2 class="heading settled" data-level="1" id="intro"><span class="secno">1. </span><span class="content">Introduction</span><a class="self-link" href="#intro"></a></h2>
   <p>In CSS Levels 1 and 2,
	image values, such as those used in the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image" id="ref-for-propdef-background-image">background-image</a> property,
	could only be given by a single URL value.
	This module introduces additional ways of representing 2D images,
	for example as <a href="#gradients">a gradient</a>.</p>
   <p>This module also defines several properties for <a href="#image-processing">manipulating raster images</a> and for <a href="#the-object-fit">sizing</a> or <a href="#the-object-position">positioning</a> replaced elements such as images within the box determined by the CSS layout algorithms.
	It also defines in a generic way CSS’s <a href="#sizing">sizing algorithm</a> for images and other similar replaced elements.</p>
   <p><em>This subsection (above) is not normative.</em></p>
   <h3 class="heading settled" data-level="1.1" id="placement"><span class="secno">1.1. </span><span class="content">Module Interactions</span><a class="self-link" href="#placement"></a></h3>
   <p>This module defines and extends the <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image④">&lt;image></a> value type
	defined in <a data-link-type="biblio" href="#biblio-css-values-3">[CSS-VALUES-3]</a>.
	It also replaces the <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#url-value" id="ref-for-url-value①">&lt;url></a> type with <span class="production" id="ref-for-typedef-image⑤">&lt;image></span> in the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image" id="ref-for-propdef-background-image①">background-image</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-ui-4/#propdef-cursor" id="ref-for-propdef-cursor">cursor</a>, and <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-image" id="ref-for-propdef-list-style-image">list-style-image</a> definitions in CSS1 and CSS2
	and adds <span class="production" id="ref-for-typedef-image⑥">&lt;image></span> as an alternative to <span class="production" id="ref-for-url-value②">&lt;url></span> in the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-content-3/#propdef-content" id="ref-for-propdef-content">content</a> property’s value.
	It is presumed that CSS specifications beyond CSS2.1
	will use the <span class="production" id="ref-for-typedef-image⑦">&lt;image></span> notation in place of <span class="production" id="ref-for-url-value③">&lt;url></span> where 2D images are expected.
	(See e.g. <a data-link-type="biblio" href="#biblio-css3bg">[CSS3BG]</a>.)</p>
   <p>None of the properties defined in this module, only <a class="property" data-link-type="propdesc" href="#propdef-image-rendering" id="ref-for-propdef-image-rendering">image-rendering</a> applies to <code>::first-line</code> and <code>::first-letter</code>.</p>
   <h3 class="heading settled" data-level="1.2" id="values"><span class="secno">1.2. </span><span class="content">Values</span><a class="self-link" href="#values"></a></h3>
   <p>This specification follows
	the <a href="https://www.w3.org/TR/CSS2/about.html#property-defs">CSS property definition conventions</a> from <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a>.
	Value types not defined in this specification are defined in CSS Level 2 Revision 1 <span>[CSS2]</span>.
	Other CSS modules may expand the definitions of these value types:
	for example <a data-link-type="biblio" href="#biblio-css-values-3">[CSS-VALUES-3]</a>, when combined with this module,
	adds the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-cascade-4/#valdef-all-initial" id="ref-for-valdef-all-initial">initial</a> keyword as a possible property value.</p>
   <p>In addition to the property-specific values listed in their definitions,
	all properties defined in this specification also accept the <a href="https://www.w3.org/TR/CSS2/cascade.html#value-def-inherit">inherit</a> keyword as their property value.
	For readability it has not been repeated explicitly.</p>
   <h2 class="heading settled" data-level="2" id="image-values"><span class="secno">2. </span><span class="content">Image Values: the <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image⑧">&lt;image></a> type</span><a class="self-link" href="#image-values"></a></h2>
   <p>The <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image⑨">&lt;image></a> value type denotes a 2D image.
	It can be a <a href="#url-notation">url reference</a> or a <a href="#gradients">color gradient</a>.
	Its syntax is:</p>
<pre class="prod"><dfn class="dfn-paneled" data-dfn-type="type" data-export id="typedef-image">&lt;image></dfn> = <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#url-value" id="ref-for-url-value④">&lt;url></a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one">|</a> <a class="production" data-link-type="type" href="#typedef-gradient" id="ref-for-typedef-gradient">&lt;gradient></a></pre>
   <p>An <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image①⓪">&lt;image></a> can be used in many CSS properties,
	including the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image" id="ref-for-propdef-background-image②">background-image</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-image" id="ref-for-propdef-list-style-image①">list-style-image</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-ui-4/#propdef-cursor" id="ref-for-propdef-cursor①">cursor</a> properties <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a> (where it replaces the <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#url-value" id="ref-for-url-value⑤">&lt;url></a> component in the property’s value).</p>
   <p>In some cases an image is invalid,
	such as a <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#url-value" id="ref-for-url-value⑥">&lt;url></a> pointing to a resource that is not a valid image format
	or that has failed to load.
	An <dfn class="dfn-paneled" data-dfn-type="dfn" data-export data-lt="invalid image|valid image" id="invalid-image">invalid image</dfn> is rendered as a solid-color <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-color-4/#valdef-color-transparent" id="ref-for-valdef-color-transparent">transparent</a> image with no intrinsic dimensions.
	However, <a data-link-type="dfn" href="#invalid-image" id="ref-for-invalid-image">invalid images</a> can trigger error-handling clauses
	in some contexts.
	For example, an <span id="ref-for-invalid-image①">invalid image</span> in <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-image" id="ref-for-propdef-list-style-image②">list-style-image</a> is treated as <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-lists-3/#valdef-list-style-type-none" id="ref-for-valdef-list-style-type-none">none</a>,
	allowing the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-type" id="ref-for-propdef-list-style-type">list-style-type</a> to render in its place. <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a></p>
   <p>While an image is loading,
	is is a <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="loading-image">loading image</dfn>. <a data-link-type="dfn" href="#loading-image" id="ref-for-loading-image">Loading images</a> are <em>not</em> <a data-link-type="dfn" href="#invalid-image" id="ref-for-invalid-image②">invalid images</a>,
	but have similar behavior:
	they are rendered as a solid-color <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-color-4/#valdef-color-transparent" id="ref-for-valdef-color-transparent①">transparent</a> image with no intrinsic dimensions,
	and may trigger fallback rendering in contexts that offer it,
	but must not trigger loading of fallback resources.
	Alternately, if a <span id="ref-for-loading-image①">loading image</span> happens to be replacing
	an already-loaded image
	(for example due to changes in the document or style sheet)
	and the UA is tracking this information,
	it may continue to render the already-loaded image
	in place of the <span id="ref-for-loading-image②">loading image</span>.</p>
   <p>Partially-loaded images (whose <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions">intrinsic dimensions</a> are known, but whose image data is not fully loaded)
	may be either treated as <a data-link-type="dfn" href="#loading-image" id="ref-for-loading-image③">loading images</a> or as loaded images rendered with partial data.
	For example, a UA may render an interlaced GIF in place
	as soon as its first pass of pixel data has loaded
	or even as soon as the image header (which contains sizing data) has parsed
	and refresh the rendering as more data loads;
	or it may wait until the entire image has loaded before using it.</p>
   <p>A <dfn data-dfn-type="dfn" data-export id="computed-image"><a data-link-type="dfn" href="https://drafts.csswg.org/css-cascade-4/#computed-value" id="ref-for-computed-value">computed</a> <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image①①">&lt;image></a><a class="self-link" href="#computed-image"></a></dfn> value
	is the <a data-link-type="dfn" href="https://drafts.csswg.org/css-cascade-4/#specified-value" id="ref-for-specified-value">specified value</a> with any <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#url-value" id="ref-for-url-value⑦">&lt;url></a>s, <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-color-3/#valuea-def-color" id="ref-for-valuea-def-color" title="Expands to: indigo | gold | firebrick | indianred | yellow | darkolivegreen | darkseagreen | slategrey | darkslategrey | mediumvioletred | mediumorchid | transparent | chartreuse | mediumslateblue | black | springgreen | crimson | lightsalmon | brown | turquoise | olivedrab | cyan | silver | skyblue | gray | darkturquoise | goldenrod | darkgreen | darkviolet | darkgray | lightpink | teal | darkmagenta | lightgoldenrodyellow | lavender | yellowgreen | thistle | violet | navy | dimgrey | orchid | blue | ghostwhite | honeydew | cornflowerblue | darkblue | darkkhaki | mediumpurple | cornsilk | red | bisque | slategray | darkcyan | khaki | wheat | deepskyblue | rebeccapurple | darkred | steelblue | aliceblue | lightslategrey | gainsboro | mediumturquoise | floralwhite | coral | purple | lightgrey | lightcyan | darksalmon | beige | azure | lightsteelblue | oldlace | greenyellow | royalblue | lightseagreen | mistyrose | sienna | lightcoral | orangered | navajowhite | lime | palegreen | burlywood | seashell | mediumspringgreen | fuchsia | papayawhip | blanchedalmond | peru | aquamarine | white | darkslategray | tomato | ivory | dodgerblue | currentcolor | lemonchiffon | chocolate | orange | forestgreen | darkgrey | olive | mintcream | antiquewhite | darkorange | cadetblue | moccasin | limegreen | saddlebrown | grey | darkslateblue | lightskyblue | deeppink | plum | aqua | darkgoldenrod | maroon | sandybrown | magenta | tan | rosybrown | pink | lightblue | palevioletred | mediumseagreen | slateblue | dimgray | powderblue | seagreen | snow | mediumblue | midnightblue | paleturquoise | palegoldenrod | whitesmoke | darkorchid | salmon | lightslategray | lawngreen | lightgreen | lightgray | hotpink | lightyellow | lavenderblush | linen | mediumaquamarine | green | blueviolet | peachpuff">&lt;color></a>s, and <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#length-value" id="ref-for-length-value" title="Expands to: em | vb | ch | cm | vh | vi | in | ex | vw | ic | pt | px | lh | pc | rem | rlh | vmax | advance measure | vmin | mm | cap | q">&lt;length></a>s computed.</p>
   <h3 class="heading settled" data-level="2.1" id="url-notation"><span class="secno">2.1. </span><span class="content">Image References: the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-values-4/#funcdef-url" id="ref-for-funcdef-url">url()</a> notation</span><a class="self-link" href="#url-notation"></a></h3>
   <p>The simplest way to indicate an image is to reference an image file by URL.
	This can be done with the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-values-4/#funcdef-url" id="ref-for-funcdef-url①">url()</a> notation, defined in <a data-link-type="biblio" href="#biblio-css-values-3">[CSS-VALUES-3]</a>.</p>
   <div class="example" id="example-4bc4e081">
    <a class="self-link" href="#example-4bc4e081"></a> In the example below, a background image is specified with <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-values-4/#funcdef-url" id="ref-for-funcdef-url②">url()</a>syntax: 
<pre>background-image: url(wavy.png);</pre>
   </div>
   <p>If the UA cannot download, parse, or otherwise successfully display
	the contents at the URL as an image
	(i.e. if the image is not fully <a href="https://html.spec.whatwg.org/multipage/webappapis.html#concept-imagebitmap-good">fully decodable</a>)
	it must be treated as an <a data-link-type="dfn" href="#invalid-image" id="ref-for-invalid-image③">invalid image</a>.</p>
   <h4 class="heading settled" data-level="2.1.1" id="ambiguous-urls"><span class="secno">2.1.1. </span><span class="content">Ambiguous Reference-or-Image URLs</span><a class="self-link" href="#ambiguous-urls"></a></h4>
   <p>URLs are used in many contexts for many types of resources,
	and therefore can be interpreted in many ways.
	Usually the context the URL appears in
	makes it clear how to interpret the resource,
	but in some instances
	it can be ambiguous.
	For example,
	a <a class="property" data-link-type="propdesc" href="https://drafts.fxtf.org/css-masking-1/#propdef-mask-image" id="ref-for-propdef-mask-image">mask-image</a> <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#url-value" id="ref-for-url-value⑧">&lt;url></a> value pointing to an SVG file
	could be interpreted as a reference to an element in the file
	or as an <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image①②">&lt;image></a>.</p>
   <p>An <dfn class="dfn-paneled" data-dfn-for="CSS" data-dfn-type="dfn" data-export id="css-ambiguous-image-url">ambiguous image URL</dfn> is
	a <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#url-value" id="ref-for-url-value⑨">&lt;url></a> value that can be interpreted
	as either an <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image①③">&lt;image></a> or an element reference.
	If an <a data-link-type="dfn" href="#css-ambiguous-image-url" id="ref-for-css-ambiguous-image-url">ambiguous image URL</a> is a <a href="https://www.w3.org/TR/css3-values/#local-urls">fragment-only URL</a>,
	then it must be treated as an element reference.
	Otherwise, if the <span id="ref-for-css-ambiguous-image-url①">ambiguous image URL</span> has a fragment
	that references an element in the resource
	that is an appropriate type of element for the context in which the <span class="production" id="ref-for-url-value①⓪">&lt;url></span> appears
	(such as a <code><a data-link-type="element" href="https://drafts.fxtf.org/css-masking-1/#elementdef-mask" id="ref-for-elementdef-mask">mask</a></code> element for the <a class="property" data-link-type="propdesc" href="https://drafts.fxtf.org/css-masking-1/#propdef-mask-image" id="ref-for-propdef-mask-image①">mask-image</a> property),
	it is interpreted as an element reference.
	Otherwise, it is treated as an <span class="production" id="ref-for-typedef-image①④">&lt;image></span>.</p>
   <p>Specs using the <a data-link-type="dfn" href="#css-ambiguous-image-url" id="ref-for-css-ambiguous-image-url②">ambiguous image URL</a> concept
	must define what elements are valid references for the URL,
	and any additional conditions that might apply.</p>
   <div class="example" id="example-73bb4dd5">
    <a class="self-link" href="#example-73bb4dd5"></a> For example,
		a reference like <a class="css" data-link-type="propdesc" href="https://drafts.fxtf.org/css-masking-1/#propdef-mask-image" id="ref-for-propdef-mask-image②">mask-image: url(icon.svg#foo)</a> might be pointing to a <code>&lt;mask id="foo"></code> element in the SVG document, <em>or</em> be pointing to a <code>&lt;g id="foo"></code> element
		and depending on the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/selectors-4/#target-pseudo" id="ref-for-target-pseudo">:target</a> pseudo-class to change how it renders as an image. 
    <p>When this occurs,
		the "icon.svg" file is loaded up and examined;
		if the #foo element is indeed a <code><a data-link-type="element" href="https://drafts.fxtf.org/css-masking-1/#elementdef-mask" id="ref-for-elementdef-mask①">mask</a></code>,
		the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-values-4/#funcdef-url" id="ref-for-funcdef-url③">url()</a> is treated as a reference to that element;
		otherwise,
		it’s interpreted as an image.</p>
   </div>
   <h2 class="heading settled" data-level="3" id="gradients"><span class="secno">3. </span><span class="content">Gradients</span><a class="self-link" href="#gradients"></a></h2>
   <p>A gradient is an image that smoothly fades from one color to another.
	These are commonly used for subtle shading in background images, buttons, and many other things.
	The <dfn class="dfn-paneled" data-dfn-type="dfn" data-export data-lt="gradient function" id="gradient-function">gradient functions</dfn> described in this section allow an author to specify such an image in a terse syntax,
	so that the UA can generate the image automatically when rendering the page.
	The syntax of a <a class="production css" data-link-type="type" href="#typedef-gradient" id="ref-for-typedef-gradient①">&lt;gradient></a> is:</p>
<pre class="prod"><dfn class="dfn-paneled" data-dfn-type="type" data-export id="typedef-gradient">&lt;gradient></dfn> =
  <a class="production" data-link-type="function" href="#funcdef-linear-gradient" id="ref-for-funcdef-linear-gradient">&lt;linear-gradient()></a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①">|</a> <a class="production" data-link-type="function" href="#funcdef-repeating-linear-gradient" id="ref-for-funcdef-repeating-linear-gradient">&lt;repeating-linear-gradient()></a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one②">|</a>
  <a class="production" data-link-type="function" href="#funcdef-radial-gradient" id="ref-for-funcdef-radial-gradient">&lt;radial-gradient()></a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one③">|</a> <a class="production" data-link-type="function" href="#funcdef-repeating-radial-gradient" id="ref-for-funcdef-repeating-radial-gradient">&lt;repeating-radial-gradient()></a>
</pre>
   <div class="example" id="example-3bdc7fad">
    <a class="self-link" href="#example-3bdc7fad"></a> 
    <p>As with the other <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image①⑤">&lt;image></a> types defined in this specification,
		gradients can be used in any property that accepts images.
		For example:</p>
    <ul>
     <li data-md>
      <p><code>background: linear-gradient(white, gray);</code></p>
     <li data-md>
      <p><code>list-style-image: radial-gradient(circle, #006, #00a 90%, #0000af 100%, white 100%)</code></p>
    </ul>
   </div>
   <p>A gradient is drawn into a box with the dimensions of the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size">concrete object size</a>,
	referred to as the <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="gradient-box">gradient box</dfn>.
	However, the gradient itself has no <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions①">intrinsic dimensions</a>.</p>
   <div class="example" id="example-aa187bec"><a class="self-link" href="#example-aa187bec"></a> For example, if you use a gradient as a background,
		by default the gradient will draw into a <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box">gradient box</a> the size of the element’s padding box.
		If <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size" id="ref-for-propdef-background-size">background-size</a> is explicitly set to a value such as <span class="css">100px 200px</span>,
		then the <span id="ref-for-gradient-box①">gradient box</span> will be 100px wide and 200px tall.
		Similarly, for a gradient used as a <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-image" id="ref-for-propdef-list-style-image③">list-style-image</a>,
		the box would be a 1em square,
		which is the <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size">default object size</a> for that property. </div>
   <p>Gradients are specified by defining the <dfn class="dfn-paneled" data-dfn-type="dfn" data-noexport id="starting-point">starting point</dfn> and <dfn class="dfn-paneled" data-dfn-type="dfn" data-noexport id="ending-point">ending point</dfn> of a <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="gradient-line">gradient line</dfn> (which, depending on the type of gradient,
	may geometrically be a line, or a ray, or a spiral),
	and then specifying colors at points along this line.
	The colors are smoothly blended to fill in the rest of the line,
	and then each type of gradient defines how to use the color of the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line">gradient line</a> to produce the actual gradient.</p>
   <h3 class="heading settled" data-level="3.1" id="linear-gradients"><span class="secno">3.1. </span><span class="content">Linear Gradients: the <a class="css" data-link-type="maybe" href="#funcdef-linear-gradient" id="ref-for-funcdef-linear-gradient①">linear-gradient()</a> notation</span><a class="self-link" href="#linear-gradients"></a></h3>
   <p>A linear gradient is created by specifying a straight <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line①">gradient line</a>,
	and then several colors placed along that line.
	The image is constructed by creating an infinite canvas
	and painting it with lines perpendicular to the gradient line,
	with the color of the painted line being the color of the gradient line where the two intersect.
	This produces a smooth fade from each color to the next,
	progressing in the specified direction.</p>
   <h4 class="no-toc heading settled" data-level="3.1.1" id="linear-gradient-syntax"><span class="secno">3.1.1. </span><span class="content">linear-gradient() syntax</span><a class="self-link" href="#linear-gradient-syntax"></a></h4>
   <p>The linear gradient syntax is:</p>
<pre class="prod"><dfn class="dfn-paneled" data-dfn-type="function" data-export id="funcdef-linear-gradient">linear-gradient()</dfn> = linear-gradient(
  [ <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value" title="Expands to: turn | rad | grad | deg">&lt;angle></a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one④">|</a> to <a class="production" data-link-type="type" href="#typedef-side-or-corner" id="ref-for-typedef-side-or-corner">&lt;side-or-corner></a> ]<a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#mult-opt" id="ref-for-mult-opt">?</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-comma" id="ref-for-comb-comma">,</a>
  <a class="production" data-link-type="type" href="#typedef-color-stop-list" id="ref-for-typedef-color-stop-list">&lt;color-stop-list></a>
)
<dfn class="dfn-paneled" data-dfn-type="type" data-export id="typedef-side-or-corner">&lt;side-or-corner></dfn> = [left <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one⑤">|</a> right] <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-any" id="ref-for-comb-any">||</a> [top <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one⑥">|</a> bottom]
</pre>
   <p>The first argument to the function specifies the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line②">gradient line</a>,
	which gives the gradient a direction and determines how color-stops are positioned.
	It may be omitted;
	if so, it defaults to <span class="css">to bottom</span>.</p>
   <p>The <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line③">gradient line’s</a> direction may be specified in two ways:</p>
   <dl>
    <dt data-md>using <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value①" title="Expands to: turn | rad | grad | deg">&lt;angle></a>
    <dd data-md>
     <p>For the purpose of this argument, <span class="css">0deg</span> points upward,
and positive angles represent clockwise rotation,
so <span class="css">90deg</span> point toward the right.</p>
     <p>The unit identifier may be omitted if the <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value②" title="Expands to: turn | rad | grad | deg">&lt;angle></a> is zero.</p>
    <dt data-md>using keywords
    <dd data-md>
     <p>If the argument is <span class="css">to top</span>, <span class="css">to right</span>, <span class="css">to bottom</span>, or <span class="css">to left</span>,
the angle of the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line④">gradient line</a> is <span class="css">0deg</span>, <span class="css">90deg</span>, <span class="css">180deg</span>, or <span class="css">270deg</span>, respectively.</p>
     <p>If the argument instead specifies a corner of the box such as <span class="css">to top left</span>,
the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line⑤">gradient line</a> must be angled such that it points into the same quadrant as the specified corner,
and is perpendicular to a line intersecting the two neighboring corners of the <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box②">gradient box</a>. <span class="note">This causes a color-stop at 50% to intersect the two neighboring corners (see <a href="#corner-gradient-example">example</a>).</span></p>
   </dl>
   <p>Starting from the center of the <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box③">gradient box</a>,
	extend a line at the specified angle in both directions.
	The ending point is the point on the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line⑥">gradient line</a> where a line drawn perpendicular to the <span id="ref-for-gradient-line⑦">gradient line</span> would intersect the corner of the <span id="ref-for-gradient-box④">gradient box</span> in the specified direction.
	The starting point is determined identically, but in the opposite direction.</p>
   <p class="note" role="note"><span>Note:</span> It is expected that the next level of this module will provide the ability to define the gradient’s direction relative to the current text direction and writing-mode.</p>
   <div class="example" id="example-b6f5099c">
    <a class="self-link" href="#example-b6f5099c"></a> 
    <div style="overflow: hidden">
      <img alt="[An image showing a box with a background shading gradually from white in the bottom-left corner to black in the top-right corner.  There is a line, illustrating the gradient line, angled at 45 degrees and passing through the center of the box.  The starting point and ending point of the gradient line are indicated by the intersection of the gradient line with two additional lines that pass through the bottom-left and top-right corners of the box.]" src="images/gradient-diagram.png" style="float: right; margin-left: 1em;"> 
     <p>This example illustrates visually how to calculate the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line⑧">gradient line</a> from the rules above.
			This shows the starting and ending point of the <span id="ref-for-gradient-line⑨">gradient line</span>,
			along with the actual gradient,
			produced by an element with <a class="css" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background" id="ref-for-propdef-background">background: linear-gradient(45deg, white, black);</a>.</p>
     <p>Notice how, though the starting point and ending point are outside of the box,
			they’re positioned precisely right so that the gradient is pure white <em>exactly</em> at the corner,
			and pure black <em>exactly</em> at the opposite corner.
			That’s intentional, and will always be true for linear gradients.</p>
    </div>
   </div>
   <div class="note" role="note">
     Given: 
    <ul>
     <li data-md>
      <p><var>A</var> the angle (in any quadrant) defining the gradient line’s direction such that 0 degrees points upwards and positive angles represent clockwise rotation,</p>
     <li data-md>
      <p><var>W</var> the width of the gradient box,</p>
     <li data-md>
      <p><var>H</var> the height of the gradient box,</p>
    </ul>
    <p>The length of the gradient line (between the <a data-link-type="dfn" href="#starting-point" id="ref-for-starting-point">starting point</a> and <a data-link-type="dfn" href="#ending-point" id="ref-for-ending-point">ending point</a>) is:</p>
    <p><code>abs(<var>W</var> * sin(<var>A</var>)) + abs(<var>H</var> * cos(<var>A</var>))</code></p>
   </div>
   <p>The gradient’s color stops are typically placed between
	the <a data-link-type="dfn" href="#starting-point" id="ref-for-starting-point①">starting point</a> and <a data-link-type="dfn" href="#ending-point" id="ref-for-ending-point①">ending point</a> on the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line①⓪">gradient line</a>,
	but this isn’t required:
	the <span id="ref-for-gradient-line①①">gradient line</span> extends infinitely in both directions.
	The starting point and ending point are merely arbitrary location markers,
	the starting point defining where 0%, 0px, etc are located when specifying color-stops,
	and the ending point defines where 100% is located.
	Color-stops are allowed to have positions before 0% or after 100%.</p>
   <p>The color of a linear gradient at any point is determined
	by finding the unique line passing through that point that is perpendicular to the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line①②">gradient line</a>.
	The point’s color is the color of the <span id="ref-for-gradient-line①③">gradient line</span> at the point where this line intersects it.</p>
   <h4 class="no-toc heading settled" data-level="3.1.2" id="linear-gradient-examples"><span class="secno">3.1.2. </span><span class="content">Linear Gradient Examples</span><a class="self-link" href="#linear-gradient-examples"></a></h4>
   <p>All of the following <a class="css" data-link-type="maybe" href="#funcdef-linear-gradient" id="ref-for-funcdef-linear-gradient②">linear-gradient()</a> examples are presumed to be backgrounds applied to a box that is 200px wide and 100px tall.</p>
   <div class="example" id="example-369769bb">
    <a class="self-link" href="#example-369769bb"></a> Below are various ways of specifying a basic vertical gradient: 
<pre>linear-gradient(yellow, blue);
linear-gradient(to bottom, yellow, blue);
linear-gradient(180deg, yellow, blue);
linear-gradient(to top, blue, yellow);
linear-gradient(to bottom, yellow 0%, blue 100%);
</pre>
    <p><img alt src="images/linear1.png"></p>
   </div>
   <div class="example" id="example-ef19999d">
    <a class="self-link" href="#example-ef19999d"></a> This demonstrates the use of an angle in the gradient.
		Note that, though the angle is not exactly the same as the angle between the corners,
		the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line①④">gradient line</a> is still sized so as to make the gradient yellow exactly at the upper-left corner,
		and blue exactly at the lower-right corner. 
<pre>linear-gradient(135deg, yellow, blue);
linear-gradient(-45deg, blue, yellow);
</pre>
    <p><img alt src="images/linear3.png"></p>
   </div>
   <div class="example" id="example-08549192">
    <a class="self-link" href="#example-08549192"></a> 
    <p>This demonstrates a 3-color gradient, and how to specify the location of a stop explicitly:</p>
<pre>linear-gradient(yellow, blue 20%, #0f0);</pre>
    <p><img alt src="images/linear4.png"></p>
   </div>
   <div class="example" id="corner-gradient-example">
    <a class="self-link" href="#corner-gradient-example"></a> This demonstrates a corner-to-corner gradient specified with keywords.
		Note how the gradient is red and blue exactly in the bottom-left and top-right corners, respectively,
		exactly like the second example.
		Additionally, the angle of the gradient is automatically computed so that the color at 50% (in this case, white)
		stretches across the top-left and bottom-right corners. 
<pre>linear-gradient(to top right, red, white, blue)</pre>
    <object data="images/gradient1.svg" height="100" width="200">(Image requires SVG)</object>
   </div>
   <h3 class="heading settled" data-level="3.2" id="radial-gradients"><span class="secno">3.2. </span><span class="content">Radial Gradients: the <a class="css" data-link-type="maybe" href="#funcdef-radial-gradient" id="ref-for-funcdef-radial-gradient①">radial-gradient()</a> notation</span><a class="self-link" href="#radial-gradients"></a></h3>
   <p>In a radial gradient,
	rather than colors smoothly fading from one side of the <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box⑤">gradient box</a> to the other
	as with linear gradients,
	they instead emerge from a single point
	and smoothly spread outward in a circular or elliptical shape.</p>
   <p>A radial gradient is specified by indicating the center of the gradient
	(where the 0% ellipse will be)
	and the size and shape of the <dfn class="dfn-paneled" data-dfn-type="dfn" data-noexport id="ending-shape">ending shape</dfn> (the 100% ellipse).
	Color stops are given as a list,
	just as for <a class="css" data-link-type="maybe" href="#funcdef-linear-gradient" id="ref-for-funcdef-linear-gradient③">linear-gradient()</a>.
	Starting from the <a data-link-type="dfn" href="#radial-gradient-gradient-center" id="ref-for-radial-gradient-gradient-center">gradient center</a> and progressing towards (and potentially beyond) the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape">ending shape</a>,
	uniformly-scaled concentric ellipses are drawn and colored
	according to the specified color stops.</p>
   <h4 class="no-toc heading settled" data-level="3.2.1" id="radial-gradient-syntax"><span class="secno">3.2.1. </span><span class="content">radial-gradient() Syntax</span><a class="self-link" href="#radial-gradient-syntax"></a></h4>
   <p>The radial gradient syntax is:</p>
<pre><dfn class="dfn-paneled" data-dfn-type="function" data-export id="funcdef-radial-gradient">radial-gradient()</dfn> = radial-gradient(
  [ <a class="production" data-link-type="type">&lt;ending-shape></a> || <a class="production" data-link-type="type" href="#typedef-size" id="ref-for-typedef-size" title="Expands to: farthest-side | closest-corner | <length-percentage>{2} | <length> | closest-side | farthest-corner | sides">&lt;size></a> ]? [ at <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position">&lt;position></a> ]? ,
  <a class="production" data-link-type="type" href="#typedef-color-stop-list" id="ref-for-typedef-color-stop-list①">&lt;color-stop-list></a>
)
</pre>
   <div class="example" id="example-c8f2f477">
    <a class="self-link" href="#example-c8f2f477"></a> Here is an example of a circular radial gradient 5em wide
		and positioned with its center in the top left corner: 
<pre>radial-gradient(5em circle at top left, yellow, blue)</pre>
   </div>
   <p class="note" role="note"><span>Note:</span> A future level may add the ability to move the focus of the gradient,
	as in the original -webkit-gradient() function.
	See <a href="http://lists.w3.org/Archives/Public/www-style/2011Nov/0210.html">proposal</a> tracked in <a href="https://github.com/w3c/csswg-drafts/issues/1575">Issue 1575</a> for "from <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position①">&lt;position></a>" and "from offset <a class="production css" data-link-type="type">&lt;offset></a>".</p>
   <p>The arguments are defined as follows:</p>
   <dl>
    <dt><dfn class="css" data-dfn-for="radial-gradient(), repeating-radial-gradient()" data-dfn-type="value" data-export id="valdef-radial-gradient-position"><a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position②">&lt;position></a><a class="self-link" href="#valdef-radial-gradient-position"></a></dfn> 
    <dd> Determines the <dfn class="dfn-paneled" data-dfn-for="radial-gradient(), repeating-radial-gradient()" data-dfn-type="dfn" data-lt="gradient center" data-noexport id="radial-gradient-gradient-center">center</dfn> of the gradient.
			The <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position③">&lt;position></a> value type
			(which is also used for <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-position" id="ref-for-propdef-background-position">background-position</a>)
			is defined in <a data-link-type="biblio" href="#biblio-css-values-3">[CSS-VALUES-3]</a>,
			and is resolved using the center-point as the object area
			and the <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box⑥">gradient box</a> as the positioning area.
			If this argument is omitted,
			it defaults to <a class="css" data-link-type="maybe" href="https://drafts.fxtf.org/fill-stroke-3/#valdef-stroke-align-center" id="ref-for-valdef-stroke-align-center">center</a>. 
    <dt><dfn class="css" data-dfn-for="radial-gradient(), repeating-radial-gradient()" data-dfn-type="value" data-export id="valdef-radial-gradient-ending-shape"><a class="production css" data-link-type="type">&lt;ending-shape></a><a class="self-link" href="#valdef-radial-gradient-ending-shape"></a></dfn> 
    <dd> Can be either <dfn class="dfn-paneled css" data-dfn-for="<ending-shape>" data-dfn-type="value" data-export id="valdef-ending-shape-circle">circle</dfn> or <dfn class="dfn-paneled css" data-dfn-for="<ending-shape>" data-dfn-type="value" data-export id="valdef-ending-shape-ellipse">ellipse</dfn>;
			determines whether the gradient’s <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape①">ending shape</a> is a circle or an ellipse, respectively.
			If <a class="production css" data-link-type="type">&lt;ending-shape></a> is omitted,
			the <span id="ref-for-ending-shape②">ending shape</span> defaults to a circle
			if the <a class="production css" data-link-type="type" href="#typedef-size" id="ref-for-typedef-size①" title="Expands to: farthest-side | closest-corner | <length-percentage>{2} | <length> | closest-side | farthest-corner | sides">&lt;size></a> is a single <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#length-value" id="ref-for-length-value①" title="Expands to: em | vb | ch | cm | vh | vi | in | ex | vw | ic | pt | px | lh | pc | rem | rlh | vmax | advance measure | vmin | mm | cap | q">&lt;length></a>,
			and to an ellipse otherwise. 
    <dt><dfn class="css" data-dfn-for="radial-gradient(), repeating-radial-gradient()" data-dfn-type="value" data-export id="valdef-radial-gradient-size"><a class="production css" data-link-type="type" href="#typedef-size" id="ref-for-typedef-size②" title="Expands to: farthest-side | closest-corner | <length-percentage>{2} | <length> | closest-side | farthest-corner | sides">&lt;size></a><a class="self-link" href="#valdef-radial-gradient-size"></a></dfn> 
    <dd>
      Determines the size of the gradient’s <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape③">ending shape</a>.
			If omitted it defaults to <a class="css" data-link-type="maybe" href="#valdef-size-farthest-corner" id="ref-for-valdef-size-farthest-corner">farthest-corner</a>.
			It can be given explicitly or by keyword.
			For the purpose of the keyword definitions,
			consider the <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box⑦">gradient box</a> edges as extending infinitely in both directions,
			rather than being finite line segments. 
     <p>If the ending-shape is an ellipse,
			its axises are aligned with the horizontal and vertical axises.</p>
     <p>Both <a class="css" data-link-type="maybe" href="#valdef-ending-shape-circle" id="ref-for-valdef-ending-shape-circle">circle</a> and <a class="css" data-link-type="maybe" href="#valdef-ending-shape-ellipse" id="ref-for-valdef-ending-shape-ellipse">ellipse</a> gradients accept the following keywords as their <dfn class="dfn-paneled css" data-dfn-for data-dfn-type="type" data-export id="typedef-size">&lt;size></dfn>:</p>
     <dl>
      <dt><dfn class="dfn-paneled css" data-dfn-for="<size>" data-dfn-type="value" data-export id="valdef-size-closest-side">closest-side</dfn> 
      <dd> The <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape④">ending shape</a> is sized so that
					it exactly meets the side of the <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box⑧">gradient box</a> closest to the gradient’s center.
					If the shape is an ellipse,
					it exactly meets the closest side in each dimension. 
      <dt><dfn class="dfn-paneled css" data-dfn-for="<size>" data-dfn-type="value" data-export id="valdef-size-farthest-side">farthest-side</dfn> 
      <dd> Same as <a class="css" data-link-type="maybe" href="#valdef-size-closest-side" id="ref-for-valdef-size-closest-side">closest-side</a>,
					except the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape⑤">ending shape</a> is sized based on the farthest side(s). 
      <dt><dfn class="dfn-paneled css" data-dfn-for="<size>" data-dfn-type="value" data-export id="valdef-size-closest-corner">closest-corner</dfn> 
      <dd> The <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape⑥">ending shape</a> is sized so that
					it passes through the corner of the <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box⑨">gradient box</a> closest to the gradient’s center.
					If the shape is an ellipse,
					the <span id="ref-for-ending-shape⑦">ending shape</span> is given the same aspect-ratio it would have if <a class="css" data-link-type="maybe" href="#valdef-size-closest-side" id="ref-for-valdef-size-closest-side①">closest-side</a> were specified. 
      <dt><dfn class="dfn-paneled css" data-dfn-for="<size>" data-dfn-type="value" data-export id="valdef-size-farthest-corner">farthest-corner</dfn> 
      <dd> Same as <a class="css" data-link-type="maybe" href="#valdef-size-closest-corner" id="ref-for-valdef-size-closest-corner">closest-corner</a>,
					except the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape⑧">ending shape</a> is sized based on the farthest corner.
					If the shape is an ellipse,
					the <span id="ref-for-ending-shape⑨">ending shape</span> is given the same aspect ratio it would have if <a class="css" data-link-type="maybe" href="#valdef-size-farthest-side" id="ref-for-valdef-size-farthest-side">farthest-side</a> were specified. 
     </dl>
     <p>If <a class="production css" data-link-type="type">&lt;ending-shape></a> is specified as <a class="css" data-link-type="maybe" href="#valdef-ending-shape-circle" id="ref-for-valdef-ending-shape-circle①">circle</a> or is omitted,
			the <a class="production css" data-link-type="type" href="#typedef-size" id="ref-for-typedef-size③" title="Expands to: farthest-side | closest-corner | <length-percentage>{2} | <length> | closest-side | farthest-corner | sides">&lt;size></a> may be given explicitly as:</p>
     <dl>
      <dt><dfn class="css" data-dfn-for="<size>" data-dfn-type="value" data-export id="valdef-size-length">&lt;length><a class="self-link" href="#valdef-size-length"></a></dfn> 
      <dd>
        Gives the radius of the circle explicitly.
					Negative values are invalid. 
       <p class="note" role="note"><span>Note:</span> Percentages are <em>not</em> allowed here;
					they can only be used to specify the size of an elliptical gradient,
					not a circular one.
					This restriction exists because there is are multiple reasonable answers as to which dimension the percentage should be relative to.
					A future level of this module may provide the ability to size circles with percentages,
					perhaps with more explicit controls over which dimension is used.</p>
     </dl>
     <p>If <a class="production css" data-link-type="type">&lt;ending-shape></a> is specified as <a class="css" data-link-type="maybe" href="#valdef-ending-shape-ellipse" id="ref-for-valdef-ending-shape-ellipse①">ellipse</a> or is omitted, <a class="production css" data-link-type="type" href="#typedef-size" id="ref-for-typedef-size④" title="Expands to: farthest-side | closest-corner | <length-percentage>{2} | <length> | closest-side | farthest-corner | sides">&lt;size></a> may instead be given explicitly as:</p>
     <dl>
      <dt><dfn class="css" data-dfn-for="<size>" data-dfn-type="value" data-export id="valdef-size-length-percentage2"><a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-length-percentage" id="ref-for-typedef-length-percentage">&lt;length-percentage></a>{2}<a class="self-link" href="#valdef-size-length-percentage2"></a></dfn> 
      <dd> Gives the size of the ellipse explicitly.
					The first value represents the horizontal radius,
					the second the vertical radius.
					Percentages values are relative to the corresponding dimension of the <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box①⓪">gradient box</a>.
					Negative values are invalid. 
     </dl>
   </dl>
   <div class="note" role="note">
     Expanded with the above definitions,
		the grammar becomes: 
<pre>radial-gradient() = radial-gradient(
  [ [ circle               || <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#length-value" id="ref-for-length-value②" title="Expands to: em | vb | ch | cm | vh | vi | in | ex | vw | ic | pt | px | lh | pc | rem | rlh | vmax | advance measure | vmin | mm | cap | q">&lt;length></a> ]                          [ at <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position④">&lt;position></a> ]? , |
    [ ellipse              || <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-length-percentage" id="ref-for-typedef-length-percentage①">&lt;length-percentage></a>{2} ]            [ at <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position⑤">&lt;position></a> ]? , |
    [ [ circle | ellipse ] || <a class="production" data-link-type="type" href="#typedef-extent-keyword" id="ref-for-typedef-extent-keyword">&lt;extent-keyword></a> ]                  [ at <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position⑥">&lt;position></a> ]? , |
    at <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position⑦">&lt;position></a> ,
  ]?
  <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-images-4/#typedef-color-stop" id="ref-for-typedef-color-stop">&lt;color-stop></a> [ , <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-images-4/#typedef-color-stop" id="ref-for-typedef-color-stop①">&lt;color-stop></a> ]+
)
<dfn class="dfn-paneled" data-dfn-type="type" data-noexport id="typedef-extent-keyword">&lt;extent-keyword></dfn> = closest-corner | closest-side | farthest-corner | farthest-side
</pre>
   </div>
   <h4 class="no-toc heading settled" data-level="3.2.2" id="radial-color-stops"><span class="secno">3.2.2. </span><span class="content">Placing Color Stops</span><a class="self-link" href="#radial-color-stops"></a></h4>
   <p>Color-stops are placed on a <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line①⑤">gradient line</a> shaped like a ray
	(a line that starts at one point, and extends infinitely in a one direction),
	similar to the <span id="ref-for-gradient-line①⑥">gradient line</span> of linear gradients.
	The <span id="ref-for-gradient-line①⑦">gradient line’s</span> <a data-link-type="dfn" href="#starting-point" id="ref-for-starting-point②">starting point</a> is at the center of the gradient,
	and it extends toward the right,
	with the <a data-link-type="dfn" href="#ending-point" id="ref-for-ending-point②">ending point</a> on the point where the <span id="ref-for-gradient-line①⑧">gradient line</span> intersects the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape①⓪">ending shape</a>.
	A color-stop can be placed at a location before 0%;
	though the negative region of the <span id="ref-for-gradient-line①⑨">gradient line</span> is never directly consulted for rendering,
	color stops placed there can affect the color of non-negative locations on the <span id="ref-for-gradient-line②⓪">gradient line</span> through interpolation or repetition
	(see <a href="#repeating-gradients">repeating gradients</a>).
	For example, <span class="css">radial-gradient(red -50px, yellow 100px)</span> produces an elliptical gradient
	that starts with a reddish-orange color in the center
	(specifically, #f50)
	and transitions to yellow.
	Locations greater than 100% simply specify a location a correspondingly greater distance from the center of the gradient.</p>
   <p>The color of the gradient at any point is determined by
	first finding the unique ellipse passing through that point
	with the same center, orientation, and ratio between major and minor axises as the ending-shape.
	The point’s color is then the color of the positive section of the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line②①">gradient line</a> at the location where this ellipse intersects it.</p>
   <h4 class="no-toc heading settled" data-level="3.2.3" id="degenerate-radials"><span class="secno">3.2.3. </span><span class="content">Degenerate Radial Gradients</span><a class="self-link" href="#degenerate-radials"></a></h4>
   <p>Some combinations of position, size, and shape
	will produce a circle or ellipse with a radius of 0.
	This will occur, for example,
	if the center is on a <a data-link-type="dfn" href="#gradient-box" id="ref-for-gradient-box①①">gradient box</a> edge and <a class="css" data-link-type="maybe" href="#valdef-size-closest-side" id="ref-for-valdef-size-closest-side②">closest-side</a> or <a class="css" data-link-type="maybe" href="#valdef-size-closest-corner" id="ref-for-valdef-size-closest-corner①">closest-corner</a> is specified
	or if the size and shape are given explicitly and either of the radiuses is zero.
	In these degenerate cases,
	the gradient must be be rendered as follows:</p>
   <dl>
    <dt data-md>If the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape①①">ending shape</a> is a circle with zero radius:
    <dd data-md>
     <p>Render as if the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape①②">ending shape</a> was
a circle whose radius was an arbitrary very small number greater than zero. <span class="note">This will make the gradient continue to look like a circle.</span></p>
    <dt data-md>If the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape①③">ending shape</a> has zero width (regardless of the height):
    <dd data-md>
     <p>Render as if the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape①④">ending shape</a> was
an ellipse whose height was an arbitrary very large number
and whose width was an arbitrary very small number greater than zero. <span class="note">This will make the gradient look similar to a horizontal linear gradient
that is mirrored across the center of the ellipse.
It also means that all color-stop positions specified with a percentage resolve to <span class="css">0px</span>.</span></p>
    <dt data-md>Otherwise, if the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape①⑤">ending shape</a> has zero height:
    <dd data-md>
     <p>Render as if the <a data-link-type="dfn" href="#ending-shape" id="ref-for-ending-shape①⑥">ending shape</a> was
an ellipse whose width was an arbitrary very large number
and whose height was an arbitrary very small number greater than zero. <span class="note">This will make the gradient look like a solid-color image
equal to the color of the last color-stop,
or equal to the average color of the gradient if it’s repeating.</span></p>
   </dl>
   <h4 class="no-toc heading settled" data-level="3.2.4" id="radial-gradient-examples"><span class="secno">3.2.4. </span><span class="content">Radial Gradient Examples</span><a class="self-link" href="#radial-gradient-examples"></a></h4>
   <p>All of the following examples are applied to a box that is 200px wide and 100px tall.</p>
   <div class="example" id="example-21e5434c">
    <a class="self-link" href="#example-21e5434c"></a> These examples demonstrate different ways to write the basic syntax for radial gradients: 
<pre>radial-gradient(yellow, green);
radial-gradient(ellipse at center, yellow 0%, green 100%);
radial-gradient(farthest-corner at 50% 50%, yellow, green);
</pre>
    <p><img alt src="images/radial1.png"></p>
<pre>radial-gradient(circle, yellow, green);</pre>
    <p><img alt src="images/radial2.png"></p>
<pre>radial-gradient(red, yellow, green);</pre>
    <p><img alt src="images/radial3.png"></p>
   </div>
   <div class="example" id="example-efad25ac">
    <a class="self-link" href="#example-efad25ac"></a> This image shows a gradient originating from somewhere other than the center of the box: 
<pre>radial-gradient(farthest-side at left bottom, red, yellow 50px, green);</pre>
    <p><img alt src="images/radial4.png"></p>
   </div>
   <div class="example" id="example-fe6adef0">
    <a class="self-link" href="#example-fe6adef0"></a> Here we illustrate a <a class="css" data-link-type="maybe" href="#valdef-size-closest-side" id="ref-for-valdef-size-closest-side③">closest-side</a> gradient. 
<pre>radial-gradient(closest-side at 20px 30px, red, yellow, green);
radial-gradient(20px 30px at 20px 30px, red, yellow, green);
</pre>
    <p><img alt src="images/radial6.png"></p>
<pre>radial-gradient(closest-side circle at 20px 30px, red, yellow, green);
radial-gradient(20px 20px at 20px 30px, red, yellow, green);
</pre>
    <p><img alt src="images/radial7.png"></p>
   </div>
   <h3 class="heading settled" data-level="3.3" id="repeating-gradients"><span class="secno">3.3. </span><span class="content">Repeating Gradients: the <a class="css" data-link-type="maybe" href="#funcdef-repeating-linear-gradient" id="ref-for-funcdef-repeating-linear-gradient①">repeating-linear-gradient()</a> and <a class="css" data-link-type="maybe" href="#funcdef-repeating-radial-gradient" id="ref-for-funcdef-repeating-radial-gradient①">repeating-radial-gradient()</a> notations</span><a class="self-link" href="#repeating-gradients"></a></h3>
   <p>In addition to <a class="css" data-link-type="maybe" href="#funcdef-linear-gradient" id="ref-for-funcdef-linear-gradient④">linear-gradient()</a> and <a class="css" data-link-type="maybe" href="#funcdef-radial-gradient" id="ref-for-funcdef-radial-gradient②">radial-gradient()</a>,
	this specification defines <dfn class="caniuse-paneled dfn-paneled css" data-dfn-type="function" data-export id="funcdef-repeating-linear-gradient">repeating-linear-gradient()</dfn> and <dfn class="dfn-paneled css" data-dfn-type="function" data-export id="funcdef-repeating-radial-gradient">repeating-radial-gradient()</dfn> values.
	These notations take the same values
	and are interpreted the same
	as their respective non-repeating siblings defined previously.</p>
   <p>When rendered, however, the color-stops are repeated infinitely in both directions,
	with their positions shifted by multiples of the difference between
	the last specified color-stop’s position
	and the first specified color-stop’s position.
	For example, <span class="css">repeating-linear-gradient(red 10px, blue 50px)</span> is equivalent to <span class="css">linear-gradient(..., red -30px, blue 10px, red 10px, blue 50px, red 50px, blue 90px, ...)</span>.
	Note that the last color-stop and first color-stop will always coincide at the boundaries of each group,
	which will produce sharp transitions if the gradient does not start and end with the same color.</p>
   <div class="example" id="example-0122a133">
    <a class="self-link" href="#example-0122a133"></a> Repeating gradient syntax is identical to that of non-repeating gradients: 
<pre>repeating-linear-gradient(red, blue 20px, red 40px)</pre>
    <p><img alt src="images/repeating1.png"></p>
<pre>repeating-radial-gradient(red, blue 20px, red 40px)</pre>
    <p><img alt src="images/repeating2.png"></p>
<pre>repeating-radial-gradient(circle closest-side at 20px 30px, red, yellow, green 100%, yellow 150%, red 200%)</pre>
    <p><img alt src="images/repeating3.png"></p>
   </div>
   <p>If the distance between the first and last color-stops is non-zero,
	but is small enough that the implementation knows that the physical resolution of the output device is insufficient to faithfully render the gradient,
	the implementation must <a data-link-type="dfn" href="#gradient-average-color" id="ref-for-gradient-average-color">find the average color of the gradient</a> and render the gradient as a solid-color image equal to the average color.</p>
   <p>If the distance between the first and last color-stops is zero
	(or rounds to zero due to implementation limitations),
	the implementation must <a data-link-type="dfn" href="#gradient-average-color" id="ref-for-gradient-average-color①">find the average color of a gradient</a> with the same number and color of color-stops,
	but with the first and last color-stop an arbitrary non-zero distance apart,
	and the remaining color-stops equally spaced between them.
	Then it must render the gradient as a solid-color image equal to that average color.</p>
   <p>If the width of the ending shape of a repeating radial gradient is non-zero
	and the height is zero,
	or is close enough to zero that the implementation knows that the physical resolution of the output device is insufficient to faithfully render the gradient,
	the implementation must <a data-link-type="dfn" href="#gradient-average-color" id="ref-for-gradient-average-color②">find the average color of the gradient</a> and render the gradient as a solid-color image equal to the average color.</p>
   <p class="note" role="note"><span>Note:</span> The <a href="#degenerate-radials">Degenerate Radial Gradients</a> section
	describes how the ending shape is adjusted when its width is zero.</p>
   <p>To <dfn class="dfn-paneled" data-dfn-type="dfn" data-lt="gradient-average-color" data-noexport id="gradient-average-color">find the average color of a gradient</dfn>,
	run these steps:</p>
   <ol>
    <li data-md>
     <p>Define <var>list</var> as an initially-empty list of premultiplied RGBA colors,
and <var>total-length</var> as the distance between first and last color stops.</p>
    <li data-md>
     <p>For each adjacent pair of color-stops,
define <var>weight</var> as half the distance between the two color-stops,
divided by <var>total-length</var>.
Add two entries to <var>list</var>,
the first obtained by representing the color of the first color-stop in premultiplied sRGBA
and scaling all of the components by <var>weight</var>,
and the second obtained in the same way with the second color-stop.</p>
    <li data-md>
     <p>Sum the entries of <var>list</var> component-wise to produce the average color,
and return it.</p>
   </ol>
   <p class="note" role="note"><span>Note:</span> As usual, implementations may use whatever algorithm they wish,
	so long as it produces the same result as the above.</p>
   <div class="example" id="example-179d6dec">
    <a class="self-link" href="#example-179d6dec"></a> For example, the following gradient is rendered as a solid light-purple image (equal to <code>rgb(75%,50%,75%)</code>): 
<pre class="css">repeating-linear-gradient(red 0px, white 0px, blue 0px);</pre>
    <p>The following gradient would render the same as the previous under normal circumstances
		(because desktop monitors can’t faithfully render color-stops 1/10th of a pixel apart),
		but would render as a normal repeating gradient if, for example,
		the author applied "zoom:100;" to the element on which the gradient appears:</p>
<pre class="css">repeating-linear-gradient(red 0px, white .1px, blue .2px);</pre>
   </div>
   <h3 class="heading settled" data-level="3.4" id="gradient-colors"><span class="secno">3.4. </span><span class="content">Defining Gradient Color</span><a class="self-link" href="#gradient-colors"></a></h3>
   <p>The colors in gradients are specified using <dfn class="dfn-paneled" data-dfn-type="dfn" data-export data-lt="color stop" id="color-stop">color stops</dfn> (a <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-color-3/#valuea-def-color" id="ref-for-valuea-def-color①" title="Expands to: indigo | gold | firebrick | indianred | yellow | darkolivegreen | darkseagreen | slategrey | darkslategrey | mediumvioletred | mediumorchid | transparent | chartreuse | mediumslateblue | black | springgreen | crimson | lightsalmon | brown | turquoise | olivedrab | cyan | silver | skyblue | gray | darkturquoise | goldenrod | darkgreen | darkviolet | darkgray | lightpink | teal | darkmagenta | lightgoldenrodyellow | lavender | yellowgreen | thistle | violet | navy | dimgrey | orchid | blue | ghostwhite | honeydew | cornflowerblue | darkblue | darkkhaki | mediumpurple | cornsilk | red | bisque | slategray | darkcyan | khaki | wheat | deepskyblue | rebeccapurple | darkred | steelblue | aliceblue | lightslategrey | gainsboro | mediumturquoise | floralwhite | coral | purple | lightgrey | lightcyan | darksalmon | beige | azure | lightsteelblue | oldlace | greenyellow | royalblue | lightseagreen | mistyrose | sienna | lightcoral | orangered | navajowhite | lime | palegreen | burlywood | seashell | mediumspringgreen | fuchsia | papayawhip | blanchedalmond | peru | aquamarine | white | darkslategray | tomato | ivory | dodgerblue | currentcolor | lemonchiffon | chocolate | orange | forestgreen | darkgrey | olive | mintcream | antiquewhite | darkorange | cadetblue | moccasin | limegreen | saddlebrown | grey | darkslateblue | lightskyblue | deeppink | plum | aqua | darkgoldenrod | maroon | sandybrown | magenta | tan | rosybrown | pink | lightblue | palevioletred | mediumseagreen | slateblue | dimgray | powderblue | seagreen | snow | mediumblue | midnightblue | paleturquoise | palegoldenrod | whitesmoke | darkorchid | salmon | lightslategray | lawngreen | lightgreen | lightgray | hotpink | lightyellow | lavenderblush | linen | mediumaquamarine | green | blueviolet | peachpuff">&lt;color></a> and a corresponding position on the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line②②">gradient line</a>)
	and <dfn class="dfn-paneled" data-dfn-type="dfn" data-export data-local-lt="transition hint" data-lt="color transition hint" id="color-transition-hint">color transition hints</dfn> (a position between two <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop">color stops</a> representing the halfway point in the color transition)
	which are placed on the <span id="ref-for-gradient-line②③">gradient line</span>,
	defining the color at every point of the line.
	(Each <a data-link-type="dfn" href="#gradient-function" id="ref-for-gradient-function">gradient function</a> defines the shape and length of the <span id="ref-for-gradient-line②④">gradient line</span>,
	along with its <a data-link-type="dfn" href="#starting-point" id="ref-for-starting-point③">starting point</a> and <a data-link-type="dfn" href="#ending-point" id="ref-for-ending-point③">ending point</a>;
	see above.)</p>
   <h4 class="heading settled" data-level="3.4.1" id="color-stop-syntax"><span class="secno">3.4.1. </span><span class="content"> Color Stop Lists</span><a class="self-link" href="#color-stop-syntax"></a></h4>
   <p><a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop①">Color stops</a> and <a data-link-type="dfn" href="#color-transition-hint" id="ref-for-color-transition-hint">transition hints</a> are specified
	in a <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="color-stop-list">color stop list</dfn>,
	which is a list of two or more <span id="ref-for-color-stop②">color stops</span> interleaved with optional <span id="ref-for-color-transition-hint①">transition hints</span>:</p>
<pre class="prod"><dfn class="dfn-paneled" data-dfn-type="type" data-export id="typedef-color-stop-list">&lt;color-stop-list></dfn> =
  <a class="production" data-link-type="type" href="#typedef-linear-color-stop" id="ref-for-typedef-linear-color-stop">&lt;linear-color-stop></a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-comma" id="ref-for-comb-comma①">,</a> [ <a class="production" data-link-type="type" href="#typedef-linear-color-hint" id="ref-for-typedef-linear-color-hint">&lt;linear-color-hint></a><a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#mult-opt" id="ref-for-mult-opt①">?</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-comma" id="ref-for-comb-comma②">,</a> <a class="production" data-link-type="type" href="#typedef-linear-color-stop" id="ref-for-typedef-linear-color-stop①">&lt;linear-color-stop></a> ]<a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#mult-comma" id="ref-for-mult-comma">#</a>
<dfn class="dfn-paneled" data-dfn-type="type" data-export id="typedef-linear-color-stop">&lt;linear-color-stop></dfn> = <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-color-3/#valuea-def-color" id="ref-for-valuea-def-color②" title="Expands to: indigo | gold | firebrick | indianred | yellow | darkolivegreen | darkseagreen | slategrey | darkslategrey | mediumvioletred | mediumorchid | transparent | chartreuse | mediumslateblue | black | springgreen | crimson | lightsalmon | brown | turquoise | olivedrab | cyan | silver | skyblue | gray | darkturquoise | goldenrod | darkgreen | darkviolet | darkgray | lightpink | teal | darkmagenta | lightgoldenrodyellow | lavender | yellowgreen | thistle | violet | navy | dimgrey | orchid | blue | ghostwhite | honeydew | cornflowerblue | darkblue | darkkhaki | mediumpurple | cornsilk | red | bisque | slategray | darkcyan | khaki | wheat | deepskyblue | rebeccapurple | darkred | steelblue | aliceblue | lightslategrey | gainsboro | mediumturquoise | floralwhite | coral | purple | lightgrey | lightcyan | darksalmon | beige | azure | lightsteelblue | oldlace | greenyellow | royalblue | lightseagreen | mistyrose | sienna | lightcoral | orangered | navajowhite | lime | palegreen | burlywood | seashell | mediumspringgreen | fuchsia | papayawhip | blanchedalmond | peru | aquamarine | white | darkslategray | tomato | ivory | dodgerblue | currentcolor | lemonchiffon | chocolate | orange | forestgreen | darkgrey | olive | mintcream | antiquewhite | darkorange | cadetblue | moccasin | limegreen | saddlebrown | grey | darkslateblue | lightskyblue | deeppink | plum | aqua | darkgoldenrod | maroon | sandybrown | magenta | tan | rosybrown | pink | lightblue | palevioletred | mediumseagreen | slateblue | dimgray | powderblue | seagreen | snow | mediumblue | midnightblue | paleturquoise | palegoldenrod | whitesmoke | darkorchid | salmon | lightslategray | lawngreen | lightgreen | lightgray | hotpink | lightyellow | lavenderblush | linen | mediumaquamarine | green | blueviolet | peachpuff">&lt;color></a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-all" id="ref-for-comb-all">&amp;&amp;</a> <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-length-percentage" id="ref-for-typedef-length-percentage②">&lt;length-percentage></a><a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#mult-opt" id="ref-for-mult-opt②">?</a>
<dfn class="dfn-paneled" data-dfn-type="type" data-export id="typedef-linear-color-hint">&lt;linear-color-hint></dfn> = <a class="production" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-length-percentage" id="ref-for-typedef-length-percentage③">&lt;length-percentage></a>
</pre>
   <p>Percentages are resolved against the length of the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line②⑤">gradient line</a> between the <a data-link-type="dfn" href="#starting-point" id="ref-for-starting-point④">starting point</a> and <a data-link-type="dfn" href="#ending-point" id="ref-for-ending-point④">ending point</a>,
	with 0% being at the starting point
	and 100% being at the ending point.
	Lengths are measured along the <span id="ref-for-gradient-line②⑥">gradient line</span> from the <span id="ref-for-starting-point⑤">starting point</span> in the direction of the <span id="ref-for-ending-point⑤">ending point</span>.</p>
   <p><a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop③">Color stop</a> and <a data-link-type="dfn" href="#color-transition-hint" id="ref-for-color-transition-hint②">transition hint</a> positions
	are usually placed between
	the <a data-link-type="dfn" href="#starting-point" id="ref-for-starting-point⑥">starting point</a> and <a data-link-type="dfn" href="#ending-point" id="ref-for-ending-point⑥">ending point</a>,
	but that’s not required:
	the gradient line extends infinitely in both directions,
	and positions can be specified anywhere
	on the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line②⑦">gradient line</a>.</p>
   <p>When the position of a <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop④">color stop</a> is omitted,
	it is automatically assigned a position.
	The first or last <span id="ref-for-color-stop⑤">color stop</span> in the <a data-link-type="dfn" href="#color-stop-list" id="ref-for-color-stop-list">color stop list</a> is assigned
	the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line②⑧">gradient line’s</a> <a data-link-type="dfn" href="#starting-point" id="ref-for-starting-point⑦">starting point</a> or <a data-link-type="dfn" href="#ending-point" id="ref-for-ending-point⑦">ending point</a> (respectively).
	Otherwise,
	it’s assigned the position halfway between the two surrounding stops.
	If multiple stops in a row lack a position,
	they space themselves out equally
	between the surrounding positioned stops.
	See <a href="#color-stop-fixup">§ 3.4.3 Color Stop “Fixup”</a> for details.</p>
   <h4 class="heading settled" data-level="3.4.2" id="coloring-gradient-line"><span class="secno">3.4.2. </span><span class="content"> Coloring the Gradient Line</span><a class="self-link" href="#coloring-gradient-line"></a></h4>
   <p>At each <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop⑥">color stop</a> position,
	the <a data-link-type="dfn" href="#gradient-line" id="ref-for-gradient-line②⑨">gradient line</a> is the color of the <span id="ref-for-color-stop⑦">color stop</span>.
	Before the first <span id="ref-for-color-stop⑧">color stop</span>,
	the <span id="ref-for-gradient-line③⓪">gradient line</span> is the color of the first <span id="ref-for-color-stop⑨">color stop</span>,
	and after the last <span id="ref-for-color-stop①⓪">color stop</span>,
	the <span id="ref-for-gradient-line③①">gradient line</span> is the color of the last <span id="ref-for-color-stop①①">color stop</span>.
	Between two <span id="ref-for-color-stop①②">color stops</span>,
	the <span id="ref-for-gradient-line③②">gradient line’s</span> color is interpolated between the colors of the two <span id="ref-for-color-stop①③">color stops</span>,
	with the interpolation taking place in <a href="#premultiplied">premultiplied RGBA space</a>.</p>
   <p>By default,
	this interpolation is linear—<wbr>at 25%, 50%, or 75% of the distance between two <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop①④">color stops</a>,
	the color is a 25%, 50%, or 75% blend of the colors of the two stops.</p>
   <p>However, if a <a data-link-type="dfn" href="#color-transition-hint" id="ref-for-color-transition-hint③">transition hint</a> was provided between two <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop①⑤">color stops</a>,
	the interpolation is non-linear,
	and controlled by the hint:</p>
   <div class="algorithm" data-algorithm="interpolate with a color hint">
    <ol>
     <li> Determine the location of the <a data-link-type="dfn" href="#color-transition-hint" id="ref-for-color-transition-hint④">transition hint</a> as a percentage of the distance between the two <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop①⑥">color stops</a>,
				denoted as a number between 0 and 1,
				where 0 indicates the hint is placed right on the first <span id="ref-for-color-stop①⑦">color stop</span>,
				and 1 indicates the hint is placed right on the second <span id="ref-for-color-stop①⑧">color stop</span>.
				Let this percentage be <var>H</var>. 
     <li> For any given point between the two color stops,
				determine the point’s location as a percentage of the distance between the two <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop①⑨">color stops</a>,
				in the same way as the previous step.
				Let this percentage be <var>P</var>. 
     <li> Let <var>C</var>, the color weighting at that point,
				be equal to <code><var>P</var><sup>log<sub><var>H</var></sub>(.5)</sup></code>. 
     <li> The color at that point is then a linear blend between the colors of the two <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop②⓪">color stops</a>,
				blending <code>(1 - <var>C</var>)</code> of the first stop and <var>C</var> of the second stop. 
    </ol>
   </div>
   <p class="note" role="note"><span>Note:</span> The <a data-link-type="dfn" href="#color-transition-hint" id="ref-for-color-transition-hint⑤">transition hint</a> specifies where the “halfway color”—<wbr>the 50% blend between the colors of the two surrounding color stops—<wbr>should be placed.
	When the hint is exactly halfway between the two surrounding color stops,
	the above interpolation algorithm
	happens to produce the ordinary linear interpolation.
	If the hint is placed anywhere else,
	it produces a smooth exponential curve
	between the surrounding color stops,
	with the “halfway color” occurring exactly where the hint specifies.</p>
   <p class="issue" id="issue-7a141efc"><a class="self-link" href="#issue-7a141efc"></a> Add a visual example of a color hint being used.</p>
   <p>If multiple <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop②①">color stops</a> have the same position,
	they produce an infinitesimal transition from the one specified first in the list
	to the one specified last.
	In effect, the color suddenly changes at that position rather than smoothly transitioning.</p>
   <details class="note" id="premultiplied">
    <summary>What does “pre-multiplied” mean?</summary>
     <a class="self-link" href="#premultiplied"></a>
    <p>A “pre-multiplied” color
		is written in a form
		where the alpha channel
		is multiplied into the color channels,
		rather than being processed independently.
		For example, a partially-transparent blue may be given as <code class="lang-css highlight"><span style=";white-space:nowrap">rgba(0, 0, 255, .5)</span></code>,
		which would then be expressed as <code><span style=";white-space:nowrap">[0, 0, 127.5, .5]</span></code> in its premultiplied representation.</p>
    <p>Interpolating colors using the premultiplied representations
		rather than the plain rgba representations
		tends to produce more attractive transitions,
		particularly when transitioning from a fully opaque color to fully transparent.</p>
    <p>Note that transitions where either the transparency or the color are held constant
		(for example, transitioning between <code class="lang-css highlight"><span style=";white-space:nowrap">rgba(255, 0, 0, 100%)</span></code> (opaque red)
		and <code class="lang-css highlight"><span style=";white-space:nowrap">rgba(0,0,255,100%)</span></code> (opaque blue),
		or <code class="lang-css highlight"><span style=";white-space:nowrap">rgba(255,0,0,100%)</span></code> (opaque red)
		and <code class="lang-css highlight"><span style=";white-space:nowrap">rgba(255,0,0,0%)</span></code> (transparent red))
		have identical results whether the color interpolation is done in premultiplied or non-premultiplied color-space.
		Differences only arise when <em>both</em> the color and transparency differ between the two endpoints.</p>
    <div class="example" id="example-77596609">
     <a class="self-link" href="#example-77596609"></a> The following example illustrates the difference between
			a gradient transitioning in pre-multiplied sRGBA
			and one transitioning (incorrectly) in non-premultiplied.
			In both of these example,
			the gradient is drawn over a white background.
			Both gradients could be written with the following value: 
<pre>linear-gradient(90deg, red, transparent, blue)</pre>
     <p>With premultiplied colors,
			transitions to or from "transparent" always look nice:</p>
     <object data="images/gradient2.svg" height="100" width="200">(Image requires SVG)</object>
     <p>On the other hand,
			if a gradient were to incorrectly transition in non-premultiplied space,
			the center of the gradient would be a noticeably grayish color,
			because "transparent" is actually a shorthand for <span class="css">rgba(0,0,0,0)</span>, or transparent black,
			meaning that the red transitions to a black
			as it loses opacity,
			and similarly with the blue’s transition:</p>
     <object data="images/gradient3.svg" height="100" width="200">(Image requires SVG)</object>
    </div>
   </details>
   <h4 class="heading settled" data-level="3.4.3" id="color-stop-fixup"><span class="secno">3.4.3. </span><span class="content"> Color Stop “Fixup”</span><a class="self-link" href="#color-stop-fixup"></a></h4>
   <p>When resolving the <a data-link-type="dfn" href="https://drafts.csswg.org/css-cascade-4/#used-value" id="ref-for-used-value">used</a> positions of each <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop②②">color stop</a>,
	the following steps must be applied <em>in order</em>:</p>
   <ol>
    <li> If the first <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop②③">color stop</a> does not have a position,
			set its position to 0%.
			If the last <span id="ref-for-color-stop②④">color stop</span> does not have a position,
			set its position to 100%. 
    <li> If a <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop②⑤">color stop</a> or <a data-link-type="dfn" href="#color-transition-hint" id="ref-for-color-transition-hint⑥">transition hint</a> has a position
			that is less than the specified position
			of any <span id="ref-for-color-stop②⑥">color stop</span> or <span id="ref-for-color-transition-hint⑦">transition hint</span> before it in the list,
			set its position to be equal to the largest specified position
			of any <span id="ref-for-color-stop②⑦">color stop</span> or <span id="ref-for-color-transition-hint⑧">transition hint</span> before it. 
    <li> If any <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop②⑧">color stop</a> still does not have a position,
			then, for each run of adjacent <span id="ref-for-color-stop②⑨">color stops</span> without positions,
			set their positions so that they are evenly spaced
			between the preceding and following <span id="ref-for-color-stop③⓪">color stops</span> with positions. 
   </ol>
   <p>After applying these rules,
	all <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop③①">color stops</a> and <a data-link-type="dfn" href="#color-transition-hint" id="ref-for-color-transition-hint⑨">transition hints</a> will have a definite position and color
	and they will be in ascending order.</p>
   <p class="note" role="note"><span>Note:</span> It is recommended that authors exercise caution
	when mixing different types of units,
	such as px, em, or %,
	as this can cause a <a data-link-type="dfn" href="#color-stop" id="ref-for-color-stop③②">color stop</a> to unintentionally try to move before an earlier one.
	For example,
	the rule <a class="css" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image" id="ref-for-propdef-background-image③">background-image: linear-gradient(yellow 100px, blue 50%)</a> wouldn’t trigger any fix-up while the background area is at least <span class="css">200px</span> tall.
	If it was <span class="css">150px</span> tall, however,
	the blue <span id="ref-for-color-stop③③">color stop’s</span> position would be equivalent to <span class="css">75px</span>,
	which precedes the yellow <span id="ref-for-color-stop③④">color stop</span>,
	and would be corrected to a position of <span class="css">100px</span>.
	Additionally, since the relative ordering of such color stops
	cannot be determined without performing layout,
	they will not interpolate smoothly in <a href="http://www.w3.org/TR/css-animations/">animations</a> or <a href="http://www.w3.org/TR/css-transitions/">transitions</a>.</p>
   <div class="example" id="example-996853e0">
    <a class="self-link" href="#example-996853e0"></a> Below are several pairs of gradients.
		The latter of each pair is a manually “fixed-up” version of the former,
		obtained by applying the above rules.
		For each pair, both gradients will render identically. <span class="note">The numbers in each arrow specify which fixup steps are invoked in the transformation.</span> 
<pre>1. linear-gradient(red, white 20%, blue)
   =1=>
   linear-gradient(red 0%, white 20%, blue 100%)

2. linear-gradient(red 40%, white, black, blue)
   =1,3=>
   linear-gradient(red 40%, white 60%, black 80%, blue 100%)

3. linear-gradient(red -50%, white, blue)
   =1,3=>
   linear-gradient(red -50%, white 25%, blue 100%)

4. linear-gradient(red -50px, white, blue)
   =1,3=>
   linear-gradient(red -50px, white calc(-25px + 50%), blue 100%)

5. linear-gradient(red 20px, white 0px, blue 40px)
   =2=>
   linear-gradient(red 20px, white 20px, blue 40px)

6. linear-gradient(red, white -50%, black 150%, blue)
   =1,2=>
   linear-gradient(red 0%, white 0%, black 150%, blue 150%)

7. linear-gradient(red 80px, white 0px, black, blue 100px)
   =2,3=>
   linear-gradient(red 80px, white 80px, black 90px, blue 100px)
</pre>
   </div>
   <h2 class="heading settled" data-level="4" id="sizing"><span class="secno">4. </span><span class="content">Sizing Images and Objects in CSS</span><a class="self-link" href="#sizing"></a></h2>
   <p>Images used in CSS may come from a number of sources:
	from binary image formats (such as gif, jpeg, etc),
	dedicated markup formats (such as SVG),
	and CSS-specific formats (such as the linear-gradient() value type defined in this specification).
	As well, a document may contain many other types of objects,
	such as video, plugins, or nested documents.
	These images and objects
	(just <dfn class="dfn-paneled" data-dfn-type="dfn" data-local-lt="object" data-noexport id="objects">objects</dfn> hereafter)
	may offer many types of sizing information to CSS,
	or none at all.
	This section defines generically the size negotiation model between the object and the CSS layout algorithms.</p>
   <h3 class="heading settled" data-level="4.1" id="sizing-terms"><span class="secno">4.1. </span><span class="content">Object-Sizing Terminology</span><a class="self-link" href="#sizing-terms"></a></h3>
   <p>In order to define this handling,
	we define a few terms,
	to make it easier to refer to various concepts:</p>
   <dl>
    <dt><dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="intrinsic-dimensions">intrinsic dimensions</dfn> 
    <dd>
      The term intrinsic dimensions refers to the set of
			the <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="intrinsic-height">intrinsic height</dfn>, <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="intrinsic-width">intrinsic width</dfn>,
			and <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="intrinsic-aspect-ratio">intrinsic aspect ratio</dfn> (the ratio between the width and height),
			each of which may or may not exist for a given <a data-link-type="dfn" href="#objects" id="ref-for-objects">object</a>.
			These intrinsic dimensions represent a preferred or natural size of the object itself;
			that is, they are not a function of the context in which the object is used.
			CSS does not define how the intrinsic dimensions are found in general. 
     <p>Raster images are an example of an <a data-link-type="dfn" href="#objects" id="ref-for-objects①">object</a> with all three intrinsic dimensions.
			SVG images designed to scale might have only an <a data-link-type="dfn" href="#intrinsic-aspect-ratio" id="ref-for-intrinsic-aspect-ratio">intrinsic aspect ratio</a>;
			SVG images can also be created with only an <a data-link-type="dfn" href="#intrinsic-width" id="ref-for-intrinsic-width">intrinsic width</a> or <a data-link-type="dfn" href="#intrinsic-height" id="ref-for-intrinsic-height">height</a>.
			CSS gradients, defined in this specification, are an example of an object with no intrinsic dimensions at all.
			Another example of this is embedded documents,
			such as the <code><a data-link-type="element" href="https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element" id="ref-for-the-iframe-element">iframe</a></code> element in HTML.
			In general, <span id="ref-for-objects②">objects</span> cannot have only two intrinsic dimensions,
			as any two automatically define the third.
			However some types of replaced elements,
			such as form controls,
			can have an <span id="ref-for-intrinsic-width①">intrinsic width</span> and an <span id="ref-for-intrinsic-height①">intrinsic height</span>,
			but no <span id="ref-for-intrinsic-aspect-ratio①">intrinsic aspect ratio</span>.</p>
     <p>If an <a data-link-type="dfn" href="#objects" id="ref-for-objects③">object</a> (such as an icon) has multiple sizes,
			then the largest size (by area) is taken as its intrinsic size.
			If it has multiple aspect ratios at that size,
			or has multiple aspect ratios and no size,
			then the aspect ratio closest to the aspect ratio of the <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size①">default object size</a> is used.
			Determine this by seeing which aspect ratio produces the largest area
			when fitting it within the <span id="ref-for-default-object-size②">default object size</span> using a <a data-link-type="dfn" href="#contain-constraint" id="ref-for-contain-constraint">contain constraint</a> fit;
			if multiple sizes tie for the largest area,
			the widest size is chosen as its intrinsic size.</p>
    <dt><dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="specified-size">specified size</dfn> 
    <dd> The specified size of an <a data-link-type="dfn" href="#objects" id="ref-for-objects④">object</a> is given by CSS,
			such as through the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-width" id="ref-for-propdef-width">width</a> and <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-height" id="ref-for-propdef-height">height</a> or <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size" id="ref-for-propdef-background-size①">background-size</a> properties.
			The specified size can be a definite width and height,
			a set of constraints,
			or a combination thereof. 
    <dt><dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="concrete-object-size">concrete object size</dfn> 
    <dd> The <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①">concrete object size</a> is the result of combining
			an <a data-link-type="dfn" href="#objects" id="ref-for-objects⑤">object’s</a> <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions②">intrinsic dimensions</a> and <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size">specified size</a> with the <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size③">default object size</a> of the context it’s used in,
			producing a rectangle with a definite width and height. 
    <dt><dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="default-object-size">default object size</dfn> 
    <dd> The <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size④">default object size</a> is a rectangle with a definite height and width
			used to determine the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②">concrete object size</a> when both the <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions③">intrinsic dimensions</a> and <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size①">specified size</a> are missing dimensions. 
   </dl>
   <h3 class="heading settled" data-level="4.2" id="object-negotiation"><span class="secno">4.2. </span><span class="content">CSS⇋Object Negotiation</span><a class="self-link" href="#object-negotiation"></a></h3>
   <p><a data-link-type="dfn" href="#objects" id="ref-for-objects⑥">Objects</a> in CSS are sized and rendered by the <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="object-size-negotiation">object size negotiation</dfn> algorithm as follows:</p>
   <ol>
    <li data-md>
     <p>When an <a data-link-type="dfn" href="#objects" id="ref-for-objects⑦">object</a> is specified in a document,
such as through a <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-values-4/#funcdef-url" id="ref-for-funcdef-url④">url()</a> value in a <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image" id="ref-for-propdef-background-image④">background-image</a> property
or a <code><a data-link-type="element-sub" href="https://html.spec.whatwg.org/multipage/embedded-content.html#attr-img-src" id="ref-for-attr-img-src">src</a></code> attribute on an <code><a data-link-type="element" href="https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element" id="ref-for-the-img-element">img</a></code> element,
CSS queries the object for its <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions④">intrinsic dimensions</a>.</p>
    <li data-md>
     <p>Using the <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions⑤">intrinsic dimensions</a>,
the <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size②">specified size</a>,
and the <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size⑤">default object size</a> for the context the <a data-link-type="dfn" href="#objects" id="ref-for-objects⑧">object</a> is used in,
CSS then computes a <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size③">concrete object size</a>.
(See the <a href="#default-sizing">following section</a>.)
This defines the size and position of the region the <span id="ref-for-objects⑨">object</span> will render in.</p>
    <li data-md>
     <p>CSS asks the <a data-link-type="dfn" href="#objects" id="ref-for-objects①⓪">object</a> to render itself at the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size④">concrete object size</a>.
CSS does not define how <span id="ref-for-objects①①">objects</span> render when the <span id="ref-for-concrete-object-size⑤">concrete object size</span> is different from the <span id="ref-for-objects①②">object’s</span> <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions⑥">intrinsic dimensions</a>.
The <span id="ref-for-objects①③">object</span> may adjust itself to match the <span id="ref-for-concrete-object-size⑥">concrete object size</span> in some way,
or even render itself larger or smaller than the <span id="ref-for-concrete-object-size⑦">concrete object size</span> to satisfy sizing constraints of its own.</p>
    <li data-md>
     <p>Unless otherwise specified by CSS,
the <a data-link-type="dfn" href="#objects" id="ref-for-objects①④">object</a> is then clipped to the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size⑧">concrete object size</a>.</p>
   </ol>
   <h3 class="heading settled" data-level="4.3" id="concrete-size-resolution"><span class="secno">4.3. </span><span class="content">Concrete Object Size Resolution</span><a class="self-link" href="#concrete-size-resolution"></a></h3>
   <p>Currently the rules for sizing <a data-link-type="dfn" href="#objects" id="ref-for-objects①⑤">objects</a> are described in each context that such <span id="ref-for-objects①⑥">objects</span> are used.
	This section defines some common sizing constraints
	and how to resolve them
	so that future specs can refer to them instead of redefining size resolution in each instance.</p>
   <h4 class="heading settled" data-level="4.3.1" id="default-sizing"><span class="secno">4.3.1. </span><span class="content">Default Sizing Algorithm</span><a class="self-link" href="#default-sizing"></a></h4>
   <p>The <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="default-sizing-algorithm">default sizing algorithm</dfn> is a set of rules commonly used to find an <a data-link-type="dfn" href="#objects" id="ref-for-objects①⑦">object’s</a> <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size⑨">concrete object size</a>.
	It resolves the simultaneous constraints presented by the <span id="ref-for-objects①⑧">object’s</span> <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions⑦">intrinsic dimensions</a> and either an unconstrained <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size③">specified size</a> or one consisting of only a definite width and/or height.</p>
   <p>Some <a data-link-type="dfn" href="#objects" id="ref-for-objects①⑨">object</a> sizing rules
	(such as those for <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-image" id="ref-for-propdef-list-style-image④">list-style-image</a>)
	correspond exactly to the <a data-link-type="dfn" href="#default-sizing-algorithm" id="ref-for-default-sizing-algorithm">default sizing algorithm</a>.
	Others
	(such as those for <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-border-image" id="ref-for-propdef-border-image">border-image</a>)
	invoke the default sizing algorithm
	but also apply additional sizing rules before arriving at a final <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①⓪">concrete object size</a>.</p>
   <p>The <a data-link-type="dfn" href="#default-sizing-algorithm" id="ref-for-default-sizing-algorithm①">default sizing algorithm</a> is defined as follows:</p>
   <ul>
    <li data-md>
     <p>If the <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size④">specified size</a> is a definite width and height,
the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①①">concrete object size</a> is given that width and height.</p>
    <li data-md>
     <p>If the <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size⑤">specified size</a> is only a width or height (but not both)
then the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①②">concrete object size</a> is given that specified width or height.
The other dimension is calculated as follows:</p>
     <ol>
      <li data-md>
       <p>If the <a data-link-type="dfn" href="#objects" id="ref-for-objects②⓪">object</a> has an <a data-link-type="dfn" href="#intrinsic-aspect-ratio" id="ref-for-intrinsic-aspect-ratio②">intrinsic aspect ratio</a>,
the missing dimension of the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①③">concrete object size</a> is calculated using the <span id="ref-for-intrinsic-aspect-ratio③">intrinsic aspect ratio</span> and the present dimension.</p>
      <li data-md>
       <p>Otherwise, if the missing dimension is present in the object’s <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions⑧">intrinsic dimensions</a>,
the missing dimension is taken from the <a data-link-type="dfn" href="#objects" id="ref-for-objects②①">object’s</a> <span id="ref-for-intrinsic-dimensions⑨">intrinsic dimensions</span>.</p>
      <li data-md>
       <p>Otherwise, the missing dimension of the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①④">concrete object size</a> is taken from the <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size⑥">default object size</a>.</p>
     </ol>
    <li data-md>
     <p>If the <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size⑥">specified size</a> has no constraints:</p>
     <ol>
      <li data-md>
       <p>If the <a data-link-type="dfn" href="#objects" id="ref-for-objects②②">object</a> has an intrinsic height or width,
its size is resolved as if its <a data-link-type="dfn" href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions①⓪">intrinsic dimensions</a> were given as the <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size⑦">specified size</a>.</p>
      <li data-md>
       <p>Otherwise, its size is resolved as a <a data-link-type="dfn" href="#contain-constraint" id="ref-for-contain-constraint①">contain constraint</a> against the <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size⑦">default object size</a>.</p>
     </ol>
   </ul>
   <h4 class="heading settled" data-level="4.3.2" id="cover-contain"><span class="secno">4.3.2. </span><span class="content">Cover and Contain Constraint Sizing</span><a class="self-link" href="#cover-contain"></a></h4>
   <p>Two other common specified sizes are the <a data-link-type="dfn" href="#contain-constraint" id="ref-for-contain-constraint②">contain constraint</a> and the <a data-link-type="dfn" href="#cover-constraint" id="ref-for-cover-constraint">cover constraint</a>,
	both of which are resolved against a specified <dfn data-dfn-type="dfn" data-export id="constraint-rectangle">constraint rectangle<a class="self-link" href="#constraint-rectangle"></a></dfn> using the <a data-link-type="dfn" href="#objects" id="ref-for-objects②③">object’s</a> <a data-link-type="dfn" href="#intrinsic-aspect-ratio" id="ref-for-intrinsic-aspect-ratio④">intrinsic aspect ratio</a>:</p>
   <ul>
    <li data-md>
     <p>A <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="contain-constraint">contain constraint</dfn> is resolved
by setting the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①⑤">concrete object size</a> to the largest rectangle that has the <a data-link-type="dfn" href="#objects" id="ref-for-objects②④">object’s</a> <a data-link-type="dfn" href="#intrinsic-aspect-ratio" id="ref-for-intrinsic-aspect-ratio⑤">intrinsic aspect ratio</a> and additionally has neither width nor height larger than the constraint rectangle’s width and height, respectively.</p>
    <li data-md>
     <p>A <dfn class="dfn-paneled" data-dfn-type="dfn" data-export id="cover-constraint">cover constraint</dfn> is resolved
by setting the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①⑥">concrete object size</a> to the smallest rectangle that has the <a data-link-type="dfn" href="#objects" id="ref-for-objects②⑤">object’s</a> <a data-link-type="dfn" href="#intrinsic-aspect-ratio" id="ref-for-intrinsic-aspect-ratio⑥">intrinsic aspect ratio</a> and additionally has neither width nor height smaller than the constraint rectangle’s width and height, respectively.</p>
   </ul>
   <p>In both cases,
	if the object doesn’t have an intrinsic aspect ratio,
	the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①⑦">concrete object size</a> is the specified constraint rectangle.</p>
   <h3 class="heading settled" data-level="4.4" id="object-sizing-examples"><span class="secno">4.4. </span><span class="content">Examples of CSS Object Sizing</span><a class="self-link" href="#object-sizing-examples"></a></h3>
   <div class="example" id="example-47bacc07">
    <a class="self-link" href="#example-47bacc07"></a> The following examples show how the <a href="https://www.w3.org/TR/CSS2/">CSS 2.1</a> and <a href="https://www.w3.org/TR/css3-background/">CSS3 Backgrounds &amp; Borders</a> sizing algorithms
		correspond to concepts defined in this specification. 
    <dl>
     <dt><a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image" id="ref-for-propdef-background-image⑤">background-image</a> 
     <dd> The rules for calculating the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①⑧">concrete object size</a> of a background
				are defined in <a href="https://www.w3.org/TR/CSS2/colors.html#background-properties">CSS2.1§14.2.1</a> and <a href="https://www.w3.org/TR/css3-background/#the-background-size">CSS3BG§3.9</a>.
				CSS2.1 uses the <a data-link-type="dfn" href="#default-sizing-algorithm" id="ref-for-default-sizing-algorithm②">default sizing algorithm</a> with no <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size⑧">specified size</a> and the <a data-link-type="dfn">background positioning area</a> as the <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size⑧">default object size</a>. <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a> In CSS3, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size" id="ref-for-propdef-background-size②">background-size</a> property can give a sizing constraint,
				invoking either the <span id="ref-for-default-sizing-algorithm③">default sizing algorithm</span> or one of the <a data-link-type="dfn" href="#contain-constraint" id="ref-for-contain-constraint③">contain</a> or <a data-link-type="dfn" href="#cover-constraint" id="ref-for-cover-constraint①">cover</a> constraints.
				The concrete object size is further adjusted in later steps if <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-repeat" id="ref-for-propdef-background-repeat">background-repeat</a> has a <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-backgrounds-3/#valdef-background-repeat-round" id="ref-for-valdef-background-repeat-round">round</a> value. <a data-link-type="biblio" href="#biblio-css3bg">[CSS3BG]</a> 
     <dt><a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-image" id="ref-for-propdef-list-style-image⑤">list-style-image</a> 
     <dd> The rules for calculating the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size①⑨">concrete object size</a> of a list-style image
				are defined in <a href="https://www.w3.org/TR/CSS2/generate.html#propdef-list-style-image">CSS2.1§12.5.1</a>.
				They use the <a data-link-type="dfn" href="#default-sizing-algorithm" id="ref-for-default-sizing-algorithm④">default sizing algorithm</a> with no <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size⑨">specified size</a> and a <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size⑨">default object size</a> of 1em square. 
     <dt><a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-border-image" id="ref-for-propdef-border-image①">border-image</a> 
     <dd> Border images are sized twice:
				first the entire image is sized to determine the slice points,
				then the slices are sized to decorate the border.
				The first sizing operation is defined in <a href="https://www.w3.org/TR/css3-background/#the-border-image-slice">CSS3BG§6.2</a> and uses the <a data-link-type="dfn" href="#default-sizing-algorithm" id="ref-for-default-sizing-algorithm⑤">default sizing algorithm</a> with no <a data-link-type="dfn" href="#specified-size" id="ref-for-specified-size①⓪">specified size</a>,
				and the <a href="https://www.w3.org/TR/css3-background/#border-image-area">border image area</a> as the <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size①⓪">default object size</a>.
				The second operation is defined in <a href="https://www.w3.org/TR/css3-background/#border-image-process">CSS3BG§6.2</a>:
				the <span id="ref-for-default-sizing-algorithm⑥">default sizing algorithm</span> is used to determine an initial size for each slice
				with the corresponding <a data-link-type="dfn">border image area</a> part as the default object size.
				By default the <span id="ref-for-specified-size①①">specified size</span> matches this <span id="ref-for-default-object-size①①">default object size</span>;
				however the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-border-image-repeat" id="ref-for-propdef-border-image-repeat">border-image-repeat</a> property can drop the specified size in one or more directions
				and may also apply an additional rounding step. <a data-link-type="biblio" href="#biblio-css3bg">[CSS3BG]</a> 
     <dt><a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-ui-4/#propdef-cursor" id="ref-for-propdef-cursor②">cursor</a> 
     <dd> The rules for calculating the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②⓪">concrete object size</a> of a cursor
				are defined in <a href="https://www.w3.org/TR/CSS2/ui.html#cursor-props">CSS2.1 § 18.1: Cursors</a>.
				The <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size①②">default object size</a> is a UA-defined size
				that should be based on the size of a typical cursor on the UA’s operating system. <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a> 
     <dt><a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-content-3/#propdef-content" id="ref-for-propdef-content①">content</a> 
     <dd> Objects inserted via the CSS2.1 <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-content-3/#propdef-content" id="ref-for-propdef-content②">content</a> property
				are anonymous <a href="https://www.w3.org/TR/CSS2/conform.html#replaced-element">replaced elements</a>,
				and are sized the same way. <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a> Note that such anonymous elements have all their non-inherited properties (including <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-width" id="ref-for-propdef-width①">width</a>, <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css2/visudet.html#propdef-height" id="ref-for-propdef-height①">height</a>, etc.)
				set to their initial values. 
     <dt><a href="https://www.w3.org/TR/CSS2/conform.html#replaced-element">replaced elements</a> 
     <dd> <a href="https://www.w3.org/TR/CSS2/">CSS 2.1</a> defines the sizing of replaced elements
				(including those inserted as <a href="https://www.w3.org/TR/CSS2/generate.html#content">generated content</a> via <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-content-3/#propdef-content" id="ref-for-propdef-content③">content</a>)
				in sections <a href="https://www.w3.org/TR/CSS2/visudet.html#inline-replaced-width">10.3.2</a>, <a href="https://www.w3.org/TR/CSS2/visudet.html#min-max-widths">10.4</a>, <a href="https://www.w3.org/TR/CSS2/visudet.html#inline-replaced-height">10.6.2</a>,
				and <a href="https://www.w3.org/TR/CSS2/visudet.html#min-max-heights">10.7</a>. <a data-link-type="biblio" href="#biblio-css2">[CSS2]</a> The <a class="property" data-link-type="propdesc" href="#propdef-object-fit" id="ref-for-propdef-object-fit">object-fit</a> property defined below defines how the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②①">concrete object size</a> corresponds to the element’s used width and height;
				by default they coincide. 
    </dl>
   </div>
   <h3 class="heading settled" data-level="4.5" id="the-object-fit"><span class="secno">4.5. </span><span class="content">Sizing Objects: the <a class="property" data-link-type="propdesc" href="#propdef-object-fit" id="ref-for-propdef-object-fit①">object-fit</a> property</span><a class="self-link" href="#the-object-fit"></a></h3>
   <table class="def propdef" data-link-for-hint="object-fit">
    <tbody>
     <tr>
      <th>Name:
      <td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-object-fit">object-fit</dfn>
     <tr class="value">
      <th><a href="https://drafts.csswg.org/css-values/#value-defs">Value:</a>
      <td class="prod">fill <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one⑦">|</a> contain <span id="ref-for-comb-one⑧">|</span> cover <span id="ref-for-comb-one⑨">|</span> none <span id="ref-for-comb-one①⓪">|</span> scale-down 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#initial-values">Initial:</a>
      <td>fill 
     <tr>
      <th>Applies to:
      <td>replaced elements 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#inherited-property">Inherited:</a>
      <td>no 
     <tr>
      <th><a href="https://drafts.csswg.org/css-values/#percentages">Percentages:</a>
      <td>n/a 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#computed">Computed value:</a>
      <td>specified keyword 
     <tr>
      <th>Canonical order:
      <td>per grammar 
     <tr>
      <th><a href="https://drafts.csswg.org/web-animations/#animation-type">Animation type:</a>
      <td>discrete 
   </table>
   <p>The <a class="property" data-link-type="propdesc" href="#propdef-object-fit" id="ref-for-propdef-object-fit②">object-fit</a> property specifies how the contents of a replaced element
	should be fitted to the box established by its used height and width.</p>
   <dl>
    <dt><dfn class="css" data-dfn-for="object-fit" data-dfn-type="value" data-export id="valdef-object-fit-fill">fill<a class="self-link" href="#valdef-object-fit-fill"></a></dfn> 
    <dd> The replaced content is sized to fill the element’s content box:
			the object’s <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②②">concrete object size</a> is the element’s used width and height. 
    <dt><dfn class="dfn-paneled css" data-dfn-for="object-fit" data-dfn-type="value" data-export id="valdef-object-fit-contain">contain</dfn> 
    <dd> The replaced content is sized to maintain its aspect ratio
			while fitting within the element’s content box:
			its <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②③">concrete object size</a> is resolved as a <a data-link-type="dfn" href="#contain-constraint" id="ref-for-contain-constraint④">contain constraint</a> against the element’s used width and height. 
    <dt><dfn class="css" data-dfn-for="object-fit" data-dfn-type="value" data-export id="valdef-object-fit-cover">cover<a class="self-link" href="#valdef-object-fit-cover"></a></dfn> 
    <dd> The replaced content is sized to maintain its aspect ratio
			while filling the element’s entire content box:
			its <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②④">concrete object size</a> is resolved as a <a data-link-type="dfn" href="#cover-constraint" id="ref-for-cover-constraint②">cover constraint</a> against the element’s used width and height. 
    <dt><dfn class="dfn-paneled css" data-dfn-for="object-fit" data-dfn-type="value" data-export id="valdef-object-fit-none">none</dfn> 
    <dd> The replaced content is not resized to fit inside the element’s content box:
			determine the object’s <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②⑤">concrete object size</a> using the <a data-link-type="dfn" href="#default-sizing-algorithm" id="ref-for-default-sizing-algorithm⑦">default sizing algorithm</a> with no specified size,
			and a <a data-link-type="dfn" href="#default-object-size" id="ref-for-default-object-size①③">default object size</a> equal to the replaced element’s used width and height. 
    <dt><dfn class="dfn-paneled css" data-dfn-for="object-fit" data-dfn-type="value" data-export id="valdef-object-fit-scale-down">scale-down</dfn> 
    <dd>
      Size the content as if <a class="css" data-link-type="maybe" href="#valdef-object-fit-none" id="ref-for-valdef-object-fit-none">none</a> or <a class="css" data-link-type="maybe" href="#valdef-object-fit-contain" id="ref-for-valdef-object-fit-contain">contain</a> were specified,
			whichever would result in a smaller <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②⑥">concrete object size</a>. 
     <p class="note" role="note"><span>Note:</span> Both <a class="css" data-link-type="maybe" href="#valdef-object-fit-none" id="ref-for-valdef-object-fit-none①">none</a> and <a class="css" data-link-type="maybe" href="#valdef-object-fit-contain" id="ref-for-valdef-object-fit-contain①">contain</a> respect the content’s intrinsic aspect ratio,
			so the concept of "smaller" is well-defined.</p>
   </dl>
   <p>If the content does not completely fill the replaced element’s content box,
	the unfilled space shows the replaced element’s background.
	Since replaced elements always clip their contents to the content box,
	the content will never overflow.
	See the <a class="property" data-link-type="propdesc" href="#propdef-object-position" id="ref-for-propdef-object-position">object-position</a> property for positioning the object with respect to the content box.</p>
   <figure>
     <img alt src="images/img_scale.png" style="border: thin solid black;"> 
    <figcaption> An example showing how four of the values of <a class="property" data-link-type="propdesc" href="#propdef-object-fit" id="ref-for-propdef-object-fit③">object-fit</a> cause the replaced element (blue figure)
			to be scaled to fit its height/width box (shown with a green background),
			using the initial value for <a class="property" data-link-type="propdesc" href="#propdef-object-position" id="ref-for-propdef-object-position①">object-position</a>.
			The fifth value, <a class="css" data-link-type="maybe" href="#valdef-object-fit-scale-down" id="ref-for-valdef-object-fit-scale-down">scale-down</a>,
			in this case looks identical to <a class="css" data-link-type="maybe" href="#valdef-object-fit-contain" id="ref-for-valdef-object-fit-contain②">contain</a>. </figcaption>
   </figure>
   <p class="note" role="note"><span>Note:</span> The <a class="property" data-link-type="propdesc" href="#propdef-object-fit" id="ref-for-propdef-object-fit④">object-fit</a> property has similar semantics to
	the <code>fit</code> attribute in <a data-link-type="biblio" href="#biblio-smil10">[SMIL10]</a> and the <a class="production css" data-link-type="type">&lt;meetOrSlice></a> parameter
	on the <a href="https://www.w3.org/TR/SVG11/coords.html#PreserveAspectRatioAttribute"><code>preserveAspectRatio</code> attribute</a> in <a data-link-type="biblio" href="#biblio-svg11">[SVG11]</a>.</p>
   <p class="note" role="note"><span>Note:</span> Per the <a data-link-type="dfn" href="#object-size-negotiation" id="ref-for-object-size-negotiation">object size negotiation</a> algorithm,
	the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②⑦">concrete object size</a> (or, in this case, the size of the content)
	does not directly scale the object itself -
	it is merely passed to the object as information about the size of the visible canvas.
	How to then draw into that size is up to the image format.
	In particular, raster images always scale to the given size,
	while SVG uses the given size as the size of the "SVG Viewport"
	(a term defined by SVG)
	and then uses the values of several attributes on the root <code>&lt;svg></code> element to determine how to draw itself.</p>
   <h3 class="heading settled" data-level="4.6" id="the-object-position"><span class="secno">4.6. </span><span class="content">Positioning Objects: the <a class="property" data-link-type="propdesc" href="#propdef-object-position" id="ref-for-propdef-object-position②">object-position</a> property</span><a class="self-link" href="#the-object-position"></a></h3>
   <table class="def propdef" data-link-for-hint="object-position">
    <tbody>
     <tr>
      <th>Name:
      <td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-object-position">object-position</dfn>
     <tr class="value">
      <th><a href="https://drafts.csswg.org/css-values/#value-defs">Value:</a>
      <td class="prod"><a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position⑧">&lt;position></a> 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#initial-values">Initial:</a>
      <td>50% 50% 
     <tr>
      <th>Applies to:
      <td>replaced elements 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#inherited-property">Inherited:</a>
      <td>no 
     <tr>
      <th><a href="https://drafts.csswg.org/css-values/#percentages">Percentages:</a>
      <td>refer to width and height of element itself 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#computed">Computed value:</a>
      <td>as for <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-position" id="ref-for-propdef-background-position①">background-position</a> 
     <tr>
      <th>Canonical order:
      <td>the horizontal component of the <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position⑨">&lt;position></a>, followed by the vertical component 
     <tr>
      <th><a href="https://drafts.csswg.org/web-animations/#animation-type">Animation type:</a>
      <td>as for <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-position" id="ref-for-propdef-background-position②">background-position</a> 
   </table>
   <p>The <a class="property" data-link-type="propdesc" href="#propdef-object-position" id="ref-for-propdef-object-position③">object-position</a> property determines the alignment of the replaced element inside its box.
	The <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-4/#typedef-position" id="ref-for-typedef-position①⓪">&lt;position></a> value type
	(which is also used for <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-position" id="ref-for-propdef-background-position③">background-position</a>)
	is defined in <a data-link-type="biblio" href="#biblio-css-values-3">[CSS-VALUES-3]</a>,
	and is resolved using the <a data-link-type="dfn" href="#concrete-object-size" id="ref-for-concrete-object-size②⑧">concrete object size</a> as the object area
	and the content box as the positioning area.</p>
   <p class="note" role="note"><span>Note:</span> Areas of the box not covered by the replaced element will show the element’s background.</p>
   <h2 class="heading settled" data-level="5" id="image-processing"><span class="secno">5. </span><span class="content">Image Processing</span><a class="self-link" href="#image-processing"></a></h2>
   <h3 class="heading settled caniuse-paneled" data-level="5.1" id="the-image-orientation"><span class="secno">5.1. </span><span class="content">Orienting an Image on the Page: the <a class="property" data-link-type="propdesc" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation①">image-orientation</a> property </span><a class="self-link" href="#the-image-orientation"></a></h3>
   <p>If a picture is taken with a camera turned on its side,
	or a document isn’t positioned correctly within a scanner,
	the resultant image may be "sideways" or even upside-down.
	The <a class="property" data-link-type="propdesc" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation②">image-orientation</a> property provides a way to apply an "out-of-band" rotation to image source data to correctly orient an image.</p>
   <p class="note" role="note"><span>Note:</span> This property is not intended to specify layout transformations
	such as arbitrary rotation or flipping the image in the horizontal or vertical direction.
	(See <a data-link-type="biblio" href="#biblio-css-transforms-1">[CSS-TRANSFORMS-1]</a> for a feature designed to do that.)
	It is also not needed to correctly orient an image when printing in landscape versus portrait orientation,
	as that rotation is done as part of layout. (See <a data-link-type="biblio" href="#biblio-css3page">[CSS3PAGE]</a>.)
	It should only be used to correct incorrectly-oriented images.</p>
   <table class="def propdef" data-link-for-hint="image-orientation">
    <tbody>
     <tr>
      <th>Name:
      <td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-image-orientation">image-orientation</dfn>
     <tr class="value">
      <th><a href="https://drafts.csswg.org/css-values/#value-defs">Value:</a>
      <td class="prod">from-image <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①①">|</a> none <span id="ref-for-comb-one①②">|</span> <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value③" title="Expands to: turn | rad | grad | deg">&lt;angle></a> <span id="ref-for-comb-one①③">|</span> [ <span class="production" id="ref-for-angle-value④" title="Expands to: turn | rad | grad | deg">&lt;angle></span><a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#mult-opt" id="ref-for-mult-opt③">?</a> flip ] 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#initial-values">Initial:</a>
      <td>from-image 
     <tr>
      <th>Applies to:
      <td><a href="https://drafts.csswg.org/css-pseudo/#generated-content" title="Includes ::before and ::after pseudo-elements.">all elements</a> 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#inherited-property">Inherited:</a>
      <td>yes 
     <tr>
      <th><a href="https://drafts.csswg.org/css-values/#percentages">Percentages:</a>
      <td>n/a 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#computed">Computed value:</a>
      <td>the specified keyword, or an <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value⑤" title="Expands to: turn | rad | grad | deg">&lt;angle></a>, rounded and normalized (see text), plus optionally a <span class="css">flip</span> keyword 
     <tr>
      <th>Canonical order:
      <td>per grammar 
     <tr>
      <th><a href="https://drafts.csswg.org/web-animations/#animation-type">Animation type:</a>
      <td>discrete 
   </table>
   <p><strong>This property is deprecated,
	and is <em>optional</em> for implementations.</strong></p>
   <p class="note" role="note"><span>Note:</span> This property previously used <a class="css" data-link-type="maybe" href="#valdef-image-orientation-none" id="ref-for-valdef-image-orientation-none">none</a> as its initial value.
	It is believed that using <a class="css" data-link-type="maybe" href="#valdef-image-orientation-from-image" id="ref-for-valdef-image-orientation-from-image">from-image</a> as the initial value
	will produce a generally better user experience,
	and minimal breakage,
	but future compat data as UAs attempt to make the change will confirm that.
	If that is confirmed, then it is likely that this property will be removed from CSS
	unless use cases other than “correct for incorrect orientation” are raised for its other values.</p>
   <p>This property specifies an orthogonal rotation to be applied to an image before it is laid out.
	It applies only to content images
	(e.g. replaced elements and generated content),
	not decorative images
	(such as <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image" id="ref-for-propdef-background-image⑥">background-image</a>).
	CSS layout processing applies to the image <em>after</em> rotation.
	This implies, for example:</p>
   <ul>
    <li data-md>
     <p>The intrinsic height and width are derived from the rotated rather than the original image dimensions.</p>
    <li data-md>
     <p>The height (width) property applies to the vertical (horizontal) dimension of the image, <em>after</em> rotation.</p>
   </ul>
   <p>Values have the following meanings:</p>
   <dl>
    <dt><dfn class="dfn-paneled css" data-dfn-for="image-orientation" data-dfn-type="value" data-export id="valdef-image-orientation-none">none</dfn> 
    <dd> No additional rotation is applied:
			the image is oriented as encoded. 
    <dt><dfn class="dfn-paneled css" data-dfn-for="image-orientation" data-dfn-type="value" data-export id="valdef-image-orientation-from-image">from-image</dfn> 
    <dd> If the image has an orientation specified in its metadata,
			such as EXIF,
			this value computes to the angle that the metadata specifies is necessary to correctly orient the image.
			If necessary, this angle is then rounded and normalized as described above for an <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value⑥" title="Expands to: turn | rad | grad | deg">&lt;angle></a> value.
			If there is no orientation specified in its metadata,
			this value computes to <a class="css" data-link-type="maybe" href="#valdef-image-orientation-none" id="ref-for-valdef-image-orientation-none①">none</a>. 
    <dt><dfn class="css" data-dfn-for="image-orientation" data-dfn-type="value" data-export id="valdef-image-orientation-angle"><a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value⑦" title="Expands to: turn | rad | grad | deg">&lt;angle></a><a class="self-link" href="#valdef-image-orientation-angle"></a></dfn> 
    <dd> Positive values cause the image to be rotated to the right
			(in a clockwise direction),
			while negative values cause a rotation to the left.
			The computed value of the property is calculated
			by moduloing the value by <span class="css">1turn</span> (so that it lies in the half-open range [<span class="css">0turn</span>, <span class="css">1turn</span>)),
			then rounding it to the nearest quarter-turn,
			rounding away from 0
			(so <span class="css">45deg</span> rounds to <span class="css">90deg</span>, etc). 
    <dt><dfn class="css" data-dfn-for="image-orientation" data-dfn-type="value" data-export id="valdef-image-orientation-angle-flip"><a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value⑧" title="Expands to: turn | rad | grad | deg">&lt;angle></a>? flip<a class="self-link" href="#valdef-image-orientation-angle-flip"></a></dfn> 
    <dd>
      Identical to the plain <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#angle-value" id="ref-for-angle-value⑨" title="Expands to: turn | rad | grad | deg">&lt;angle></a> case,
			except that after rotation the image is flipped horizontally.
			If the <span class="production" id="ref-for-angle-value①⓪" title="Expands to: turn | rad | grad | deg">&lt;angle></span> is omitted,
			it defaults to <span class="css">0deg</span>. 
     <p class="note" role="note"><span>Note:</span> This value is only necessary to represent all 8 possible EXIF orientations that <a class="css" data-link-type="value" href="#valdef-image-orientation-from-image" id="ref-for-valdef-image-orientation-from-image①">from-image</a> can produce.</p>
   </dl>
   <p>The <a class="property" data-link-type="propdesc" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation③">image-orientation</a> property must be applied before any other transformations,
	such as using CSS Transforms.</p>
   <div class="example" id="example-5e0592b8">
    <a class="self-link" href="#example-5e0592b8"></a> The following example rotates the image 90 degrees clockwise: 
<pre>img.ninety     { image-orientation: 90deg }
...
&lt;img class="ninety" src=...>
</pre>
    <p>The same effect could be achieved with, for example,
		an angle of -270deg or 450deg.</p>
   </div>
   <h3 class="heading settled" data-level="5.2" id="the-image-rendering"><span class="secno">5.2. </span><span class="content">Determining How To Scale an Image: the <a class="property" data-link-type="propdesc" href="#propdef-image-rendering" id="ref-for-propdef-image-rendering①">image-rendering</a> property</span><a class="self-link" href="#the-image-rendering"></a></h3>
   <table class="def propdef" data-link-for-hint="image-rendering">
    <tbody>
     <tr>
      <th>Name:
      <td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-image-rendering">image-rendering</dfn>
     <tr class="value">
      <th><a href="https://drafts.csswg.org/css-values/#value-defs">Value:</a>
      <td class="prod">auto <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①④">|</a> smooth <span id="ref-for-comb-one①⑤">|</span> high-quality <span id="ref-for-comb-one①⑥">|</span> crisp-edges <span id="ref-for-comb-one①⑦">|</span> pixelated 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#initial-values">Initial:</a>
      <td>auto 
     <tr>
      <th>Applies to:
      <td><a href="https://drafts.csswg.org/css-pseudo/#generated-content" title="Includes ::before and ::after pseudo-elements.">all elements</a> 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#inherited-property">Inherited:</a>
      <td>yes 
     <tr>
      <th><a href="https://drafts.csswg.org/css-values/#percentages">Percentages:</a>
      <td>n/a 
     <tr>
      <th><a href="https://drafts.csswg.org/css-cascade/#computed">Computed value:</a>
      <td>specified keyword 
     <tr>
      <th>Canonical order:
      <td>per grammar 
     <tr>
      <th><a href="https://drafts.csswg.org/web-animations/#animation-type">Animation type:</a>
      <td>discrete 
   </table>
   <p>The <a class="property" data-link-type="propdesc" href="#propdef-image-rendering" id="ref-for-propdef-image-rendering②">image-rendering</a> property provides a hint to the user-agent
	about what aspects of an image are most important to preserve when the image is scaled,
	to aid the user-agent in the choice of an appropriate scaling algorithm.
	When specified on an element,
	it applies to all images given in properties for the element,
	such as background images,
	list-style images,
	or the content of replaced elements when they represent an image that must be scaled.
	The values of the <span class="property" id="ref-for-propdef-image-rendering③">image-rendering</span> property are interpreted as follows:</p>
   <dl>
    <dt><dfn class="dfn-paneled css" data-dfn-for="image-rendering" data-dfn-type="value" data-export id="valdef-image-rendering-auto">auto</dfn> 
    <dd> The scaling algorithm is UA dependent. 
    <dt><dfn class="dfn-paneled css" data-dfn-for="image-rendering" data-dfn-type="value" data-export id="valdef-image-rendering-smooth">smooth</dfn> 
    <dd> The image should be scaled with an algorithm that maximizes the appearance of the image.
			In particular, scaling algorithms that "smooth" colors are acceptable,
			such as bilinear interpolation.
			This is intended for images such as photos. 
    <dt><dfn class="dfn-paneled css" data-dfn-for="image-rendering" data-dfn-type="value" data-export id="valdef-image-rendering-high-quality">high-quality</dfn> 
    <dd>
      Identical to <a class="css" data-link-type="maybe" href="#valdef-image-rendering-smooth" id="ref-for-valdef-image-rendering-smooth">smooth</a>,
			but with a preference for higher-quality scaling.
			If system resources are constrained,
			images with <a class="css" data-link-type="maybe" href="#valdef-image-rendering-high-quality" id="ref-for-valdef-image-rendering-high-quality">high-quality</a> should be prioritized over those with any other value,
			when considering which images to degrade the quality of
			and to what degree. 
     <div class="note" role="note">
       This value <em>does not</em> prevent the image quality from being degraded
				when the system resources are constrained.
				It merely expresses a preference that these images should receive extra scaling resources
				relative to the <a class="css" data-link-type="maybe" href="#valdef-image-rendering-auto" id="ref-for-valdef-image-rendering-auto">auto</a> images.
				If all images on the page have <a class="css" data-link-type="maybe" href="#valdef-image-rendering-high-quality" id="ref-for-valdef-image-rendering-high-quality①">high-quality</a> applied,
				it’s equivalent to all of them having <span class="css" id="ref-for-valdef-image-rendering-auto①">auto</span> applied—<wbr>they’re all treated the same. 
      <p>To get the most value out of <a class="css" data-link-type="maybe" href="#valdef-image-rendering-high-quality" id="ref-for-valdef-image-rendering-high-quality②">high-quality</a>,
				only apply it to the most important images on the page.</p>
     </div>
    <dt><dfn class="caniuse-paneled dfn-paneled css" data-dfn-for="image-rendering" data-dfn-type="value" data-export id="valdef-image-rendering-crisp-edges">crisp-edges</dfn> 
    <dd> The image must be scaled with an algorithm that preserves contrast and edges in the image,
			and which does not smooth colors or introduce blur to the image in the process.
			This is intended for images such as pixel art or line drawings. 
    <dt><dfn class="dfn-paneled css" data-dfn-for="image-rendering" data-dfn-type="value" data-export id="valdef-image-rendering-pixelated">pixelated</dfn> 
    <dd> The image must be scaled with the "nearest neighbor" or similar algorithm,
			to preserve a "pixelated" look as the image changes in size. 
   </dl>
   <p>This property does not dictate any particular scaling algorithm to be used.
	For example, with <a class="css" data-link-type="propdesc" href="#propdef-image-rendering" id="ref-for-propdef-image-rendering④">image-rendering: auto</a>,
	a user agent might scale images with bilinear interpolation by default,
	switch to nearest-neighbor interpolation in high-load situations,
	and switch to a high-quality scaling algorithm like Lanczos interpolation for static images that aren’t moving or changing.
	Similarly, with 'image-rendering: crisp-edges',
	a user agent might scale images with nearest-neighbor interpolation by default,
	and switch to EPX interpolation in low-load situations.</p>
   <div class="example" id="example-448b3881">
    <a class="self-link" href="#example-448b3881"></a> For example, given the following small image: 
    <figure>
      <img src="images/pixel-art-small.gif"> 
     <figcaption>A small pixel-art image. </figcaption>
    </figure>
    <p>Scaling it up 3x might look like the following,
		depending on the value of <a class="property" data-link-type="propdesc" href="#propdef-image-rendering" id="ref-for-propdef-image-rendering⑤">image-rendering</a>:</p>
    <figure>
      <img src="images/pixel-art-small.gif" width="384"> 
     <figcaption>The image scaled with <a class="css" data-link-type="maybe" href="#valdef-image-rendering-auto" id="ref-for-valdef-image-rendering-auto②">auto</a></figcaption>
    </figure>
    <figure>
      <img src="images/pixel-art-nn.png"> 
     <figcaption>The image scaled with <a class="css" data-link-type="maybe" href="#valdef-image-rendering-pixelated" id="ref-for-valdef-image-rendering-pixelated">pixelated</a></figcaption>
    </figure>
    <figure>
      <img src="images/pixel-art-smooth.png"> 
     <figcaption> The image scaled with <a class="css" data-link-type="maybe" href="#valdef-image-rendering-crisp-edges" id="ref-for-valdef-image-rendering-crisp-edges">crisp-edges</a>.<br> <small>(Or it might look like <a class="css" data-link-type="maybe" href="#valdef-image-rendering-pixelated" id="ref-for-valdef-image-rendering-pixelated①">pixelated</a>,
				or as another type of pixel-scaling algorithm,
				depending on the browser.)</small> </figcaption>
    </figure>
   </div>
   <p>This property previously accepted the values <span class="css">optimizeSpeed</span> and <span class="css">optimizeQuality</span>.
	These are now deprecated;
	a user agent must accept them as valid values
	but must treat them as having the same behavior as <a class="css" data-link-type="maybe" href="#valdef-image-rendering-pixelated" id="ref-for-valdef-image-rendering-pixelated②">pixelated</a> and <a class="css" data-link-type="maybe" href="#valdef-image-rendering-smooth" id="ref-for-valdef-image-rendering-smooth①">smooth</a> respectively,
	and authors must not use them.</p>
   <h2 class="heading settled" data-level="6" id="interpolation"><span class="secno">6. </span><span class="content">Interpolation</span><a class="self-link" href="#interpolation"></a></h2>
   <p>Interpolation of <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image①⑥">&lt;image></a> values is not defined in this level.
	Implementations must abruptly transition them
	(at 50% transition progress, like other unsupported interpolations),
	unless otherwise defined by a future specification.</p>
   <p class="note" role="note"><span>Note:</span> CSS Images Level 4 is expected to define specialized interpolation for gradients,
	and define that all other images interpolate by cross-fading.</p>
   <h2 class="heading settled" data-level="7" id="serialization"><span class="secno">7. </span><span class="content">Serialization</span><a class="self-link" href="#serialization"></a></h2>
   <p>This section describes the serialization of all new properties and value types introduced in this specification,
	for the purpose of interfacing with the CSS Object Model <a data-link-type="biblio" href="#biblio-cssom">[CSSOM]</a>.</p>
   <p>To serialize any function defined in this module,
	serialize it per its individual grammar,
	in the order its grammar is written in,
	omitting components when possible without changing the meaning,
	joining space-separated tokens with a single space,
	and following each serialized comma with a single space.</p>
   <div class="example" id="example-33854bc0">
    <a class="self-link" href="#example-33854bc0"></a> For example, a gradient specified as: 
<pre>Linear-Gradient( to bottom, red 0%,yellow,black 100px)</pre>
    <p>must serialize as:</p>
<pre>linear-gradient(red, yellow, black 100px)</pre>
   </div>
   <h2 class="no-num heading settled" id="privsec"><span class="content"> Privacy and Security Considerations</span><a class="self-link" href="#privsec"></a></h2>
   <p>This specification allows rendering of cross-origin images by default,
which exposes some information of those images programmatically—<wbr>specifically, the intrinsic sizes and resolution of those images.</p>
   <h2 class="no-num heading settled" id="acknowledgments"><span class="content"> Acknowledgments</span><a class="self-link" href="#acknowledgments"></a></h2>
   <p>Thanks to the Webkit team, Brad Kemper, Brian Manthos, and Alan Gresley
   for their contributions to the definition of gradients; to Melinda Grant
   for her work on <a class="property" data-link-type="propdesc" href="#propdef-object-fit" id="ref-for-propdef-object-fit⑤">object-fit</a>, <a class="property" data-link-type="propdesc" href="#propdef-object-position" id="ref-for-propdef-object-position④">object-position</a>, and <a class="property" data-link-type="propdesc" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation④">image-orientation</a>;
 and to L. David Baron,
   Kang-Hao Lu, Leif Arne Storset, Erik Dahlstrom, and Øyvind Stenhaug for
   their careful review, comments, and corrections.</p>
   <h2 class="no-num heading settled" id="changes"><span class="content"> Changes</span><a class="self-link" href="#changes"></a></h2>
   <h3 class="no-num heading settled" id="changes-20120407"><span class="content"> Changes Since the <a href="https://www.w3.org/TR/2012/CR-css3-images-20120417/">17 April 2012 Candidate Recommendation</a></span><a class="self-link" href="#changes-20120407"></a></h3>
   <p>Major changes include:</p>
   <ul>
    <li data-md>
     <p>The <span class="css">image()</span> notation has been deferred to Level 4.</p>
    <li data-md>
     <p>The <span class="css">image-resolution</span> property has been deferred to Level 4.</p>
    <li data-md>
     <p>The <a class="property" data-link-type="propdesc" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation⑤">image-orientation</a> property has been marked as deprecated, optional, and at-risk. Additionally:</p>
     <ul>
      <li data-md>
       <p>Added the <a class="css" data-link-type="maybe" href="#valdef-image-orientation-from-image" id="ref-for-valdef-image-orientation-from-image②">from-image</a> and <a class="css" data-link-type="maybe" href="#valdef-image-orientation-none" id="ref-for-valdef-image-orientation-none②">none</a> keywords</p>
      <li data-md>
       <p>Added the <span class="css">flip</span> values</p>
      <li data-md>
       <p><a href="https://github.com/w3c/csswg-drafts/issues/1206">Swapped to "mod then round" ordering.</a></p>
     </ul>
    <li data-md>
     <p>Added the <a class="property" data-link-type="propdesc" href="#propdef-image-rendering" id="ref-for-propdef-image-rendering⑥">image-rendering</a> property.</p>
    <li data-md>
     <p>Moved the <a class="production css" data-link-type="type" href="https://drafts.csswg.org/css-values-3/#resolution-value" id="ref-for-resolution-value" title="Expands to: dppx | x | dpcm | dpi">&lt;resolution></a> type to <a data-link-type="biblio" href="#biblio-css-values-3">[CSS-VALUES-3]</a>.</p>
    <li data-md>
     <p>Better defined the handling of invalid and partially-loaded images.</p>
    <li data-md>
     <p>Defined the general computed form of <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image①⑦">&lt;image></a>.</p>
    <li data-md>
     <p>Defined concept and handling of URLs that are ambiguous between being images or element references.</p>
    <li data-md>
     <p>Defined that the unit can be omitted for zero angles in <a class="css" data-link-type="maybe" href="#funcdef-linear-gradient" id="ref-for-funcdef-linear-gradient⑤">linear-gradient()</a> due to compat.</p>
    <li data-md>
     <p>Slightly clarified handling of degenerate repeating radial gradients.</p>
    <li data-md>
     <p>Added <a data-link-type="dfn" href="#color-transition-hint" id="ref-for-color-transition-hint①⓪">transition hints</a> to <a class="production css" data-link-type="type" href="#typedef-color-stop-list" id="ref-for-typedef-color-stop-list②">&lt;color-stop-list></a>,
and editorially rewrote section on gradient color stops to better accommodate the new prose.</p>
    <li data-md>
     <p>Added "Canonical Order" and "Animation Type" to all property definition tables.</p>
    <li data-md>
     <p>Defined interpolation and serialization of <a class="production css" data-link-type="type" href="#typedef-image" id="ref-for-typedef-image①⑧">&lt;image></a> values.</p>
    <li data-md>
     <p>Various minor clarifications.</p>
   </ul>
   <p>A <a href="https://drafts.csswg.org/issues?spec=css-images-3&amp;doc=cr-2012">Disposition of Comments</a> is available.</p>
   <h3 class="no-num heading settled" id="changes-last-call"><span class="content"> Changes Since Last Call</span><a class="self-link" href="#changes-last-call"></a></h3>
   <p>Major changes include:</p>
   <ul>
    <li data-md>
     <p>The <span class="css">element()</span> feature has been deferred to Level 4.</p>
    <li data-md>
     <p>The directional images feature
(<a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-writing-modes-4/#valdef-direction-ltr" id="ref-for-valdef-direction-ltr">ltr</a>/<a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-writing-modes-4/#valdef-direction-rtl" id="ref-for-valdef-direction-rtl">rtl</a>annotations in <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-images-4/#funcdef-image" id="ref-for-funcdef-image">image()</a>)
has been deferred to Level 4 to address some design-level feedback.</p>
    <li data-md>
     <p>Images referenced with unsupported URL fragment syntax
are now considered invalid (and trigger fallback) within <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-images-4/#funcdef-image" id="ref-for-funcdef-image①">image()</a>.</p>
    <li data-md>
     <p>The <a class="property" data-link-type="propdesc" href="#propdef-object-fit" id="ref-for-propdef-object-fit⑥">object-fit</a> property no longer resizes the element’s content box in any cases.</p>
    <li data-md>
     <p>The <a class="property" data-link-type="propdesc" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation⑥">image-orientation</a> property is now inherited.</p>
   </ul>
   <p>Significant details updated:</p>
   <ul>
    <li data-md>
     <p>There is now a definition for <a data-link-type="dfn" href="#invalid-image" id="ref-for-invalid-image④">invalid images</a>,
which trigger fallback in the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-images-4/#funcdef-image" id="ref-for-funcdef-image②">image()</a> notation.</p>
    <li data-md>
     <p>Clarified that media fragments are only required to be supported within <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-images-4/#funcdef-image" id="ref-for-funcdef-image③">image()</a> in order to satisfy the prerequisite for supporting <span class="css" id="ref-for-funcdef-image④">image()</span>.</p>
    <li data-md>
     <p>Defined how to determine the closeness of two aspect ratios
(used in the definition of <a href="#intrinsic-dimensions" id="ref-for-intrinsic-dimensions①①"><i>intrinsic dimensions</i></a>).</p>
    <li data-md>
     <p>Corrected error in which <a class="property" data-link-type="propdesc" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation⑦">image-orientation</a> was applied after CSS transforms.</p>
    <li data-md>
     <p>The <a class="property" data-link-type="propdesc" href="#propdef-object-fit" id="ref-for-propdef-object-fit⑦">object-fit</a> and <a class="property" data-link-type="propdesc" href="#propdef-object-position" id="ref-for-propdef-object-position⑤">object-position</a> properties
can no longer be aliased to <span class="css">image-fit</span> and <span class="css">image-position</span>.
A future edition of the <a href="http://www.w3.org/TR/css-print/">CSS Print Profile</a> may allow this for printer implementations, however.</p>
   </ul>
   <p>There were also many clarifications
	and several sections were rearranged to make them easier to read.</p>
   <p>The <a href="http://dev.w3.org/csswg/css3-images/issues-lc-2012">Disposition of Last Call Comments</a> is available.</p>
  </main>
  <h2 class="no-ref no-num heading settled" id="conformance"><span class="content"> Conformance</span><a class="self-link" href="#conformance"></a></h2>
  <h3 class="heading settled" id="document-conventions"><span class="content"> Document conventions</span><a class="self-link" href="#document-conventions"></a></h3>
  <p>Conformance requirements are expressed with a combination of
	descriptive assertions and RFC 2119 terminology. The key words “MUST”,
	“MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”,
	“RECOMMENDED”, “MAY”, and “OPTIONAL” in the normative parts of this
	document are to be interpreted as described in RFC 2119.
	However, for readability, these words do not appear in all uppercase
	letters in this specification. </p>
  <p>All of the text of this specification is normative except sections
	explicitly marked as non-normative, examples, and notes. <a data-link-type="biblio" href="#biblio-rfc2119">[RFC2119]</a> </p>
  <p>Examples in this specification are introduced with the words “for example”
	or are set apart from the normative text with <code>class="example"</code>,
	like this: </p>
  <div class="example" id="example-ae2b6bc0">
   <a class="self-link" href="#example-ae2b6bc0"></a> 
   <p>This is an example of an informative example. </p>
  </div>
  <p>Informative notes begin with the word “Note” and are set apart from the
	normative text with <code>class="note"</code>, like this: </p>
  <p class="note" role="note">Note, this is an informative note. </p>
  <p>Advisements are normative sections styled to evoke special attention and are
	set apart from other normative text with <code>&lt;strong class="advisement"></code>, like
	this: <strong class="advisement"> UAs MUST provide an accessible alternative. </strong> </p>
  <h3 class="heading settled" id="conform-classes"><span class="content"> Conformance classes</span><a class="self-link" href="#conform-classes"></a></h3>
  <p>Conformance to this specification
	is defined for three conformance classes: </p>
  <dl>
   <dt>style sheet 
   <dd>A <a href="http://www.w3.org/TR/CSS2/conform.html#style-sheet">CSS
			style sheet</a>. 
   <dt>renderer 
   <dd>A <a href="http://www.w3.org/TR/CSS2/conform.html#user-agent">UA</a> that interprets the semantics of a style sheet and renders
			documents that use them. 
   <dt>authoring tool 
   <dd>A <a href="http://www.w3.org/TR/CSS2/conform.html#user-agent">UA</a> that writes a style sheet. 
  </dl>
  <p>A style sheet is conformant to this specification
	if all of its statements that use syntax defined in this module are valid
	according to the generic CSS grammar and the individual grammars of each
	feature defined in this module. </p>
  <p>A renderer is conformant to this specification
	if, in addition to interpreting the style sheet as defined by the
	appropriate specifications, it supports all the features defined
	by this specification by parsing them correctly
	and rendering the document accordingly. However, the inability of a
	UA to correctly render a document due to limitations of the device
	does not make the UA non-conformant. (For example, a UA is not
	required to render color on a monochrome monitor.) </p>
  <p>An authoring tool is conformant to this specification
	if it writes style sheets that are syntactically correct according to the
	generic CSS grammar and the individual grammars of each feature in
	this module, and meet all other conformance requirements of style sheets
	as described in this module. </p>
  <h3 class="heading settled" id="conform-responsible"><span class="content"> Requirements for Responsible Implementation of CSS</span><a class="self-link" href="#conform-responsible"></a></h3>
  <p>The following sections define several conformance requirements
		for implementing CSS responsibly,
		in a way that promotes interoperability in the present and future. </p>
  <h4 class="heading settled" id="conform-partial"><span class="content"> Partial Implementations</span><a class="self-link" href="#conform-partial"></a></h4>
  <p>So that authors can exploit the forward-compatible parsing rules to assign fallback values, <strong>CSS renderers <em>must</em> treat as invalid
		(and <a href="http://www.w3.org/TR/CSS2/conform.html#ignore">ignore as appropriate</a>)
		any at-rules, properties, property values, keywords, and other syntactic constructs
		for which they have no usable level of support</strong>.
		In particular, user agents <em>must not</em> selectively ignore
		unsupported property values and honor supported values in a single multi-value property declaration:
		if any value is considered invalid (as unsupported values must be),
		CSS requires that the entire declaration be ignored. </p>
  <h4 class="heading settled" id="conform-future-proofing"><span class="content"> Implementations of Unstable and Proprietary Features</span><a class="self-link" href="#conform-future-proofing"></a></h4>
  <p>To avoid clashes with future stable CSS features,
		the CSSWG recommends <a href="http://www.w3.org/TR/CSS/#future-proofing">following best practices</a> for the implementation of <a href="http://www.w3.org/TR/CSS/#unstable">unstable</a> features and <a href="http://www.w3.org/TR/CSS/#proprietary-extension">proprietary extensions</a> to CSS. </p>
  <h4 class="heading settled" id="conform-testing"><span class="content"> Implementations of CR-level Features</span><a class="self-link" href="#conform-testing"></a></h4>
  <p>Once a specification reaches the Candidate Recommendation stage,
		implementers should release an <a data-link-type="dfn" href="http://www.w3.org/TR/CSS/#vendor-prefix">unprefixed</a> implementation
		of any CR-level feature they can demonstrate
		to be correctly implemented according to spec,
		and should avoid exposing a prefixed variant of that feature. </p>
  <p>To establish and maintain the interoperability of CSS across
		implementations, the CSS Working Group requests that non-experimental
		CSS renderers submit an implementation report (and, if necessary, the
		testcases used for that implementation report) to the W3C before
		releasing an unprefixed implementation of any CSS features. Testcases
		submitted to W3C are subject to review and correction by the CSS
		Working Group. </p>
  <p>
   Further information on submitting testcases and implementation reports
		can be found from on the CSS Working Group’s website at <a href="http://www.w3.org/Style/CSS/Test/">http://www.w3.org/Style/CSS/Test/</a>.
		Questions should be directed to the <a href="http://lists.w3.org/Archives/Public/public-css-testsuite">public-css-testsuite@w3.org</a> mailing list. 
<script src="https://www.w3.org/scripts/TR/2016/fixup.js"></script>
  </p>
  <aside class="caniuse-status" data-deco data-dfn-id="funcdef-repeating-linear-gradient">
   <input class="caniuse-panel-btn" type="button" value="⋰">
   <p class="support"><b>Support:</b><span class="android yes"><span>Android Browser</span><span>4.4+</span></span><span class="baidu yes"><span>Baidu Browser</span><span>7.12+</span></span><span class="bb yes"><span>Blackberry Browser</span><span>10+</span></span><span class="chrome yes"><span>Chrome</span><span>26+</span></span><span class="and_chr yes"><span>Chrome for Android</span><span>74+</span></span><span class="edge yes"><span>Edge</span><span>12+</span></span><span class="firefox yes"><span>Firefox</span><span>16+</span></span><span class="and_ff yes"><span>Firefox for Android</span><span>66+</span></span><span class="ie yes"><span>IE</span><span>10+</span></span><span class="ie_mob yes"><span>IE Mobile</span><span>10+</span></span><span class="kaios yes"><span>KaiOS Browser</span><span>2.5+</span></span><span class="opera yes"><span>Opera</span><span>12.1+</span></span><span class="op_mini no"><span>Opera Mini</span><span>None</span></span><span class="op_mob yes"><span>Opera Mobile</span><span>12.1+</span></span><span class="and_qq yes"><span>QQ Browser</span><span>1.2+</span></span><span class="safari yes"><span>Safari</span><span>6.1+</span></span><span class="samsung yes"><span>Samsung Internet</span><span>4+</span></span><span class="and_uc yes"><span>UC Browser for Android</span><span>11.8+</span></span><span class="ios_saf yes"><span>iOS Safari</span><span>7.0+</span></span></p>
   <p class="caniuse">Source: <a href="https://caniuse.com/#feat=css-repeating-gradients">caniuse.com</a> as of 2019-06-04</p>
  </aside>
  <aside class="caniuse-status" data-deco data-dfn-id="the-image-orientation">
   <input class="caniuse-panel-btn" type="button" value="⋰">
   <p class="support"><b>Support:</b><span class="android no"><span>Android Browser</span><span>None</span></span><span class="baidu no"><span>Baidu Browser</span><span>None</span></span><span class="bb no"><span>Blackberry Browser</span><span>None</span></span><span class="chrome no"><span>Chrome</span><span>None</span></span><span class="and_chr no"><span>Chrome for Android</span><span>None</span></span><span class="edge no"><span>Edge</span><span>None</span></span><span class="firefox yes"><span>Firefox</span><span>26+</span></span><span class="and_ff yes"><span>Firefox for Android</span><span>66+</span></span><span class="ie no"><span>IE</span><span>None</span></span><span class="ie_mob no"><span>IE Mobile</span><span>None</span></span><span class="kaios yes"><span>KaiOS Browser</span><span>2.5+</span></span><span class="opera no"><span>Opera</span><span>None</span></span><span class="op_mini no"><span>Opera Mini</span><span>None</span></span><span class="op_mob no"><span>Opera Mobile</span><span>None</span></span><span class="and_qq no"><span>QQ Browser</span><span>None</span></span><span class="safari no"><span>Safari</span><span>None</span></span><span class="samsung no"><span>Samsung Internet</span><span>None</span></span><span class="and_uc no"><span>UC Browser for Android</span><span>None</span></span><span class="ios_saf partial"><span><span>iOS Safari (limited)</span></span><span>3.2+</span></span></p>
   <p class="caniuse">Source: <a href="https://caniuse.com/#feat=css-image-orientation">caniuse.com</a> as of 2019-06-04</p>
  </aside>
  <aside class="caniuse-status" data-deco data-dfn-id="valdef-image-rendering-crisp-edges">
   <input class="caniuse-panel-btn" type="button" value="⋰">
   <p class="support"><b>Support:</b><span class="android yes"><span>Android Browser</span><span>67+</span></span><span class="baidu yes"><span>Baidu Browser</span><span>7.12+</span></span><span class="bb no"><span>Blackberry Browser</span><span>None</span></span><span class="chrome yes"><span>Chrome</span><span>41+</span></span><span class="and_chr yes"><span>Chrome for Android</span><span>74+</span></span><span class="edge yes"><span>Edge</span><span>75+</span></span><span class="firefox yes"><span>Firefox</span><span>65+</span></span><span class="and_ff no"><span>Firefox for Android</span><span>None</span></span><span class="ie no"><span>IE</span><span>None</span></span><span class="ie_mob no"><span>IE Mobile</span><span>None</span></span><span class="kaios yes"><span>KaiOS Browser</span><span>2.5+</span></span><span class="opera yes"><span>Opera</span><span>28+</span></span><span class="op_mini no"><span>Opera Mini</span><span>None</span></span><span class="op_mob yes"><span>Opera Mobile</span><span>46+</span></span><span class="and_qq no"><span>QQ Browser</span><span>None</span></span><span class="safari yes"><span>Safari</span><span>10+</span></span><span class="samsung yes"><span>Samsung Internet</span><span>4+</span></span><span class="and_uc yes"><span>UC Browser for Android</span><span>11.8+</span></span><span class="ios_saf yes"><span>iOS Safari</span><span>10.0+</span></span></p>
   <p class="caniuse">Source: <a href="https://caniuse.com/#feat=css-crisp-edges">caniuse.com</a> as of 2019-06-04</p>
  </aside>
  <h2 class="no-num no-ref heading settled" id="index"><span class="content">Index</span><a class="self-link" href="#index"></a></h2>
  <h3 class="no-num no-ref heading settled" id="index-defined-here"><span class="content">Terms defined by this specification</span><a class="self-link" href="#index-defined-here"></a></h3>
  <ul class="index">
   <li><a href="#css-ambiguous-image-url">ambiguous image URL</a><span>, in §2.1.1</span>
   <li><a href="#valdef-image-orientation-angle">&lt;angle></a><span>, in §5.1</span>
   <li><a href="#valdef-image-orientation-angle-flip">&lt;angle>? flip</a><span>, in §5.1</span>
   <li><a href="#valdef-image-rendering-auto">auto</a><span>, in §5.2</span>
   <li><a href="#valdef-ending-shape-circle">circle</a><span>, in §3.2.1</span>
   <li><a href="#valdef-size-closest-corner">closest-corner</a><span>, in §3.2.1</span>
   <li><a href="#valdef-size-closest-side">closest-side</a><span>, in §3.2.1</span>
   <li><a href="#color-stop">color stop</a><span>, in §3.4</span>
   <li><a href="#color-stop-list">color stop list</a><span>, in §3.4.1</span>
   <li><a href="#typedef-color-stop-list">&lt;color-stop-list></a><span>, in §3.4.1</span>
   <li><a href="#color-transition-hint">color transition hint</a><span>, in §3.4</span>
   <li><a href="#computed-image">computed &lt;image></a><span>, in §2</span>
   <li><a href="#concrete-object-size">concrete object size</a><span>, in §4.1</span>
   <li><a href="#constraint-rectangle">constraint rectangle</a><span>, in §4.3.2</span>
   <li><a href="#valdef-object-fit-contain">contain</a><span>, in §4.5</span>
   <li><a href="#contain-constraint">contain constraint</a><span>, in §4.3.2</span>
   <li><a href="#valdef-object-fit-cover">cover</a><span>, in §4.5</span>
   <li><a href="#cover-constraint">cover constraint</a><span>, in §4.3.2</span>
   <li><a href="#valdef-image-rendering-crisp-edges">crisp-edges</a><span>, in §5.2</span>
   <li><a href="#default-object-size">default object size</a><span>, in §4.1</span>
   <li><a href="#default-sizing-algorithm">default sizing algorithm</a><span>, in §4.3.1</span>
   <li><a href="#valdef-ending-shape-ellipse">ellipse</a><span>, in §3.2.1</span>
   <li><a href="#ending-point">ending point</a><span>, in §3</span>
   <li><a href="#valdef-radial-gradient-ending-shape">&lt;ending-shape></a><span>, in §3.2.1</span>
   <li><a href="#ending-shape">ending shape</a><span>, in §3.2</span>
   <li><a href="#typedef-extent-keyword">&lt;extent-keyword></a><span>, in §3.2.1</span>
   <li><a href="#valdef-size-farthest-corner">farthest-corner</a><span>, in §3.2.1</span>
   <li><a href="#valdef-size-farthest-side">farthest-side</a><span>, in §3.2.1</span>
   <li><a href="#valdef-object-fit-fill">fill</a><span>, in §4.5</span>
   <li><a href="#valdef-image-orientation-from-image">from-image</a><span>, in §5.1</span>
   <li><a href="#typedef-gradient">&lt;gradient></a><span>, in §3</span>
   <li><a href="#gradient-average-color">gradient-average-color</a><span>, in §3.3</span>
   <li><a href="#gradient-box">gradient box</a><span>, in §3</span>
   <li><a href="#radial-gradient-gradient-center">gradient center</a><span>, in §3.2.1</span>
   <li><a href="#gradient-function">gradient function</a><span>, in §3</span>
   <li><a href="#gradient-line">gradient line</a><span>, in §3</span>
   <li><a href="#valdef-image-rendering-high-quality">high-quality</a><span>, in §5.2</span>
   <li><a href="#typedef-image">&lt;image></a><span>, in §2</span>
   <li><a href="#propdef-image-orientation">image-orientation</a><span>, in §5.1</span>
   <li><a href="#propdef-image-rendering">image-rendering</a><span>, in §5.2</span>
   <li><a href="#intrinsic-aspect-ratio">intrinsic aspect ratio</a><span>, in §4.1</span>
   <li><a href="#intrinsic-dimensions">intrinsic dimensions</a><span>, in §4.1</span>
   <li><a href="#intrinsic-height">intrinsic height</a><span>, in §4.1</span>
   <li><a href="#intrinsic-width">intrinsic width</a><span>, in §4.1</span>
   <li><a href="#invalid-image">invalid image</a><span>, in §2</span>
   <li><a href="#valdef-size-length">&lt;length></a><span>, in §3.2.1</span>
   <li><a href="#valdef-size-length-percentage2">&lt;length-percentage>{2}</a><span>, in §3.2.1</span>
   <li><a href="#typedef-linear-color-hint">&lt;linear-color-hint></a><span>, in §3.4.1</span>
   <li><a href="#typedef-linear-color-stop">&lt;linear-color-stop></a><span>, in §3.4.1</span>
   <li><a href="#funcdef-linear-gradient">linear-gradient()</a><span>, in §3.1.1</span>
   <li><a href="#loading-image">loading image</a><span>, in §2</span>
   <li>
    none
    <ul>
     <li><a href="#valdef-image-orientation-none">value for image-orientation</a><span>, in §5.1</span>
     <li><a href="#valdef-object-fit-none">value for object-fit</a><span>, in §4.5</span>
    </ul>
   <li><a href="#objects">object</a><span>, in §4</span>
   <li><a href="#propdef-object-fit">object-fit</a><span>, in §4.5</span>
   <li><a href="#propdef-object-position">object-position</a><span>, in §4.6</span>
   <li><a href="#objects">objects</a><span>, in §4</span>
   <li><a href="#object-size-negotiation">object size negotiation</a><span>, in §4.2</span>
   <li><a href="#valdef-image-rendering-pixelated">pixelated</a><span>, in §5.2</span>
   <li><a href="#valdef-radial-gradient-position">&lt;position></a><span>, in §3.2.1</span>
   <li><a href="#funcdef-radial-gradient">radial-gradient()</a><span>, in §3.2.1</span>
   <li><a href="#funcdef-repeating-linear-gradient">repeating-linear-gradient()</a><span>, in §3.3</span>
   <li><a href="#funcdef-repeating-radial-gradient">repeating-radial-gradient()</a><span>, in §3.3</span>
   <li><a href="#valdef-object-fit-scale-down">scale-down</a><span>, in §4.5</span>
   <li><a href="#typedef-side-or-corner">&lt;side-or-corner></a><span>, in §3.1.1</span>
   <li>
    &lt;size>
    <ul>
     <li><a href="#typedef-size">type for </a><span>, in §3.2.1</span>
     <li><a href="#valdef-radial-gradient-size">value for radial-gradient(), repeating-radial-gradient()</a><span>, in §3.2.1</span>
    </ul>
   <li><a href="#valdef-image-rendering-smooth">smooth</a><span>, in §5.2</span>
   <li><a href="#specified-size">specified size</a><span>, in §4.1</span>
   <li><a href="#starting-point">starting point</a><span>, in §3</span>
   <li><a href="#color-transition-hint">transition hint</a><span>, in §3.4</span>
   <li><a href="#invalid-image">valid image</a><span>, in §2</span>
  </ul>
  <aside class="dfn-panel" data-for="term-for-computed-value">
   <a href="https://drafts.csswg.org/css-cascade-4/#computed-value">https://drafts.csswg.org/css-cascade-4/#computed-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-computed-value">2. Image Values: the &lt;image> type</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-all-initial">
   <a href="https://drafts.csswg.org/css-cascade-4/#valdef-all-initial">https://drafts.csswg.org/css-cascade-4/#valdef-all-initial</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-all-initial">1.2. Values</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-specified-value">
   <a href="https://drafts.csswg.org/css-cascade-4/#specified-value">https://drafts.csswg.org/css-cascade-4/#specified-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-specified-value">2. Image Values: the &lt;image> type</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-used-value">
   <a href="https://drafts.csswg.org/css-cascade-4/#used-value">https://drafts.csswg.org/css-cascade-4/#used-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-used-value">3.4.3. 
Color Stop “Fixup”</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valuea-def-color">
   <a href="https://drafts.csswg.org/css-color-3/#valuea-def-color">https://drafts.csswg.org/css-color-3/#valuea-def-color</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valuea-def-color">2. Image Values: the &lt;image> type</a>
    <li><a href="#ref-for-valuea-def-color①">3.4. Defining Gradient Color</a>
    <li><a href="#ref-for-valuea-def-color②">3.4.1. 
Color Stop Lists</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-color-transparent">
   <a href="https://drafts.csswg.org/css-color-4/#valdef-color-transparent">https://drafts.csswg.org/css-color-4/#valdef-color-transparent</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-color-transparent">2. Image Values: the &lt;image> type</a> <a href="#ref-for-valdef-color-transparent①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-content">
   <a href="https://drafts.csswg.org/css-content-3/#propdef-content">https://drafts.csswg.org/css-content-3/#propdef-content</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-content">1.1. Module Interactions</a>
    <li><a href="#ref-for-propdef-content①">4.4. Examples of CSS Object Sizing</a> <a href="#ref-for-propdef-content②">(2)</a> <a href="#ref-for-propdef-content③">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-typedef-color-stop">
   <a href="https://drafts.csswg.org/css-images-4/#typedef-color-stop">https://drafts.csswg.org/css-images-4/#typedef-color-stop</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-color-stop">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-typedef-color-stop①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-funcdef-image">
   <a href="https://drafts.csswg.org/css-images-4/#funcdef-image">https://drafts.csswg.org/css-images-4/#funcdef-image</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-funcdef-image"> Changes Since Last Call</a> <a href="#ref-for-funcdef-image①">(2)</a> <a href="#ref-for-funcdef-image②">(3)</a> <a href="#ref-for-funcdef-image③">(4)</a> <a href="#ref-for-funcdef-image④">(5)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-list-style-image">
   <a href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-image">https://drafts.csswg.org/css-lists-3/#propdef-list-style-image</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-list-style-image">1.1. Module Interactions</a>
    <li><a href="#ref-for-propdef-list-style-image①">2. Image Values: the &lt;image> type</a> <a href="#ref-for-propdef-list-style-image②">(2)</a>
    <li><a href="#ref-for-propdef-list-style-image③">3. Gradients</a>
    <li><a href="#ref-for-propdef-list-style-image④">4.3.1. Default Sizing Algorithm</a>
    <li><a href="#ref-for-propdef-list-style-image⑤">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-list-style-type">
   <a href="https://drafts.csswg.org/css-lists-3/#propdef-list-style-type">https://drafts.csswg.org/css-lists-3/#propdef-list-style-type</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-list-style-type">2. Image Values: the &lt;image> type</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-list-style-type-none">
   <a href="https://drafts.csswg.org/css-lists-3/#valdef-list-style-type-none">https://drafts.csswg.org/css-lists-3/#valdef-list-style-type-none</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-list-style-type-none">2. Image Values: the &lt;image> type</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-elementdef-mask">
   <a href="https://drafts.fxtf.org/css-masking-1/#elementdef-mask">https://drafts.fxtf.org/css-masking-1/#elementdef-mask</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-elementdef-mask">2.1.1. Ambiguous Reference-or-Image URLs</a> <a href="#ref-for-elementdef-mask①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-mask-image">
   <a href="https://drafts.fxtf.org/css-masking-1/#propdef-mask-image">https://drafts.fxtf.org/css-masking-1/#propdef-mask-image</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-mask-image">2.1.1. Ambiguous Reference-or-Image URLs</a> <a href="#ref-for-propdef-mask-image①">(2)</a> <a href="#ref-for-propdef-mask-image②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-cursor">
   <a href="https://drafts.csswg.org/css-ui-4/#propdef-cursor">https://drafts.csswg.org/css-ui-4/#propdef-cursor</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-cursor">1.1. Module Interactions</a>
    <li><a href="#ref-for-propdef-cursor①">2. Image Values: the &lt;image> type</a>
    <li><a href="#ref-for-propdef-cursor②">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-angle-value">
   <a href="https://drafts.csswg.org/css-values-3/#angle-value">https://drafts.csswg.org/css-values-3/#angle-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-angle-value">3.1.1. linear-gradient() syntax</a> <a href="#ref-for-angle-value①">(2)</a> <a href="#ref-for-angle-value②">(3)</a>
    <li><a href="#ref-for-angle-value③">5.1. Orienting an Image on the Page: the image-orientation property </a> <a href="#ref-for-angle-value④">(2)</a> <a href="#ref-for-angle-value⑤">(3)</a> <a href="#ref-for-angle-value⑥">(4)</a> <a href="#ref-for-angle-value⑦">(5)</a> <a href="#ref-for-angle-value⑧">(6)</a> <a href="#ref-for-angle-value⑨">(7)</a> <a href="#ref-for-angle-value①⓪">(8)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-length-value">
   <a href="https://drafts.csswg.org/css-values-3/#length-value">https://drafts.csswg.org/css-values-3/#length-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-length-value">2. Image Values: the &lt;image> type</a>
    <li><a href="#ref-for-length-value①">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-length-value②">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-resolution-value">
   <a href="https://drafts.csswg.org/css-values-3/#resolution-value">https://drafts.csswg.org/css-values-3/#resolution-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-resolution-value"> Changes Since the 17 April 2012 Candidate Recommendation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-url-value">
   <a href="https://drafts.csswg.org/css-values-3/#url-value">https://drafts.csswg.org/css-values-3/#url-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-url-value①">1.1. Module Interactions</a> <a href="#ref-for-url-value②">(2)</a> <a href="#ref-for-url-value③">(3)</a>
    <li><a href="#ref-for-url-value④">2. Image Values: the &lt;image> type</a> <a href="#ref-for-url-value⑤">(2)</a> <a href="#ref-for-url-value⑥">(3)</a> <a href="#ref-for-url-value⑦">(4)</a>
    <li><a href="#ref-for-url-value⑧">2.1.1. Ambiguous Reference-or-Image URLs</a> <a href="#ref-for-url-value⑨">(2)</a> <a href="#ref-for-url-value①⓪">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-mult-comma">
   <a href="https://drafts.csswg.org/css-values-4/#mult-comma">https://drafts.csswg.org/css-values-4/#mult-comma</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-mult-comma">3.4.1. 
Color Stop Lists</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-comb-all">
   <a href="https://drafts.csswg.org/css-values-4/#comb-all">https://drafts.csswg.org/css-values-4/#comb-all</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-comb-all">3.4.1. 
Color Stop Lists</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-comb-comma">
   <a href="https://drafts.csswg.org/css-values-4/#comb-comma">https://drafts.csswg.org/css-values-4/#comb-comma</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-comb-comma">3.1.1. linear-gradient() syntax</a>
    <li><a href="#ref-for-comb-comma①">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-comb-comma②">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-typedef-length-percentage">
   <a href="https://drafts.csswg.org/css-values-4/#typedef-length-percentage">https://drafts.csswg.org/css-values-4/#typedef-length-percentage</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-length-percentage">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-typedef-length-percentage①">(2)</a>
    <li><a href="#ref-for-typedef-length-percentage②">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-typedef-length-percentage③">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-typedef-position">
   <a href="https://drafts.csswg.org/css-values-4/#typedef-position">https://drafts.csswg.org/css-values-4/#typedef-position</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-position">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-typedef-position①">(2)</a> <a href="#ref-for-typedef-position②">(3)</a> <a href="#ref-for-typedef-position③">(4)</a> <a href="#ref-for-typedef-position④">(5)</a> <a href="#ref-for-typedef-position⑤">(6)</a> <a href="#ref-for-typedef-position⑥">(7)</a> <a href="#ref-for-typedef-position⑦">(8)</a>
    <li><a href="#ref-for-typedef-position⑧">4.6. Positioning Objects: the object-position property</a> <a href="#ref-for-typedef-position⑨">(2)</a> <a href="#ref-for-typedef-position①⓪">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-mult-opt">
   <a href="https://drafts.csswg.org/css-values-4/#mult-opt">https://drafts.csswg.org/css-values-4/#mult-opt</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-mult-opt">3.1.1. linear-gradient() syntax</a>
    <li><a href="#ref-for-mult-opt①">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-mult-opt②">(2)</a>
    <li><a href="#ref-for-mult-opt③">5.1. Orienting an Image on the Page: the image-orientation property </a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-funcdef-url">
   <a href="https://drafts.csswg.org/css-values-4/#funcdef-url">https://drafts.csswg.org/css-values-4/#funcdef-url</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-funcdef-url">2.1. Image References: the url() notation</a> <a href="#ref-for-funcdef-url①">(2)</a> <a href="#ref-for-funcdef-url②">(3)</a>
    <li><a href="#ref-for-funcdef-url③">2.1.1. Ambiguous Reference-or-Image URLs</a>
    <li><a href="#ref-for-funcdef-url④">4.2. CSS⇋Object Negotiation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-comb-one">
   <a href="https://drafts.csswg.org/css-values-4/#comb-one">https://drafts.csswg.org/css-values-4/#comb-one</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-comb-one">2. Image Values: the &lt;image> type</a>
    <li><a href="#ref-for-comb-one①">3. Gradients</a> <a href="#ref-for-comb-one②">(2)</a> <a href="#ref-for-comb-one③">(3)</a>
    <li><a href="#ref-for-comb-one④">3.1.1. linear-gradient() syntax</a> <a href="#ref-for-comb-one⑤">(2)</a> <a href="#ref-for-comb-one⑥">(3)</a>
    <li><a href="#ref-for-comb-one⑦">4.5. Sizing Objects: the object-fit property</a> <a href="#ref-for-comb-one⑧">(2)</a> <a href="#ref-for-comb-one⑨">(3)</a> <a href="#ref-for-comb-one①⓪">(4)</a>
    <li><a href="#ref-for-comb-one①①">5.1. Orienting an Image on the Page: the image-orientation property </a> <a href="#ref-for-comb-one①②">(2)</a> <a href="#ref-for-comb-one①③">(3)</a>
    <li><a href="#ref-for-comb-one①④">5.2. Determining How To Scale an Image: the image-rendering property</a> <a href="#ref-for-comb-one①⑤">(2)</a> <a href="#ref-for-comb-one①⑥">(3)</a> <a href="#ref-for-comb-one①⑦">(4)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-comb-any">
   <a href="https://drafts.csswg.org/css-values-4/#comb-any">https://drafts.csswg.org/css-values-4/#comb-any</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-comb-any">3.1.1. linear-gradient() syntax</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-direction-ltr">
   <a href="https://drafts.csswg.org/css-writing-modes-4/#valdef-direction-ltr">https://drafts.csswg.org/css-writing-modes-4/#valdef-direction-ltr</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-direction-ltr"> Changes Since Last Call</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-direction-rtl">
   <a href="https://drafts.csswg.org/css-writing-modes-4/#valdef-direction-rtl">https://drafts.csswg.org/css-writing-modes-4/#valdef-direction-rtl</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-direction-rtl"> Changes Since Last Call</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-height">
   <a href="https://drafts.csswg.org/css2/visudet.html#propdef-height">https://drafts.csswg.org/css2/visudet.html#propdef-height</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-height">4.1. Object-Sizing Terminology</a>
    <li><a href="#ref-for-propdef-height①">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-width">
   <a href="https://drafts.csswg.org/css2/visudet.html#propdef-width">https://drafts.csswg.org/css2/visudet.html#propdef-width</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-width">4.1. Object-Sizing Terminology</a>
    <li><a href="#ref-for-propdef-width①">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-background">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background">https://drafts.csswg.org/css-backgrounds-3/#propdef-background</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-background">3.1.1. linear-gradient() syntax</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-background-image">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image">https://drafts.csswg.org/css-backgrounds-3/#propdef-background-image</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-background-image">1. Introduction</a>
    <li><a href="#ref-for-propdef-background-image①">1.1. Module Interactions</a>
    <li><a href="#ref-for-propdef-background-image②">2. Image Values: the &lt;image> type</a>
    <li><a href="#ref-for-propdef-background-image③">3.4.3. 
Color Stop “Fixup”</a>
    <li><a href="#ref-for-propdef-background-image④">4.2. CSS⇋Object Negotiation</a>
    <li><a href="#ref-for-propdef-background-image⑤">4.4. Examples of CSS Object Sizing</a>
    <li><a href="#ref-for-propdef-background-image⑥">5.1. Orienting an Image on the Page: the image-orientation property </a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-background-position">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-position">https://drafts.csswg.org/css-backgrounds-3/#propdef-background-position</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-background-position">3.2.1. radial-gradient() Syntax</a>
    <li><a href="#ref-for-propdef-background-position①">4.6. Positioning Objects: the object-position property</a> <a href="#ref-for-propdef-background-position②">(2)</a> <a href="#ref-for-propdef-background-position③">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-background-repeat">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-repeat">https://drafts.csswg.org/css-backgrounds-3/#propdef-background-repeat</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-background-repeat">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-background-size">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size">https://drafts.csswg.org/css-backgrounds-3/#propdef-background-size</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-background-size">3. Gradients</a>
    <li><a href="#ref-for-propdef-background-size①">4.1. Object-Sizing Terminology</a>
    <li><a href="#ref-for-propdef-background-size②">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-border-image">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#propdef-border-image">https://drafts.csswg.org/css-backgrounds-3/#propdef-border-image</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-border-image">4.3.1. Default Sizing Algorithm</a>
    <li><a href="#ref-for-propdef-border-image①">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-propdef-border-image-repeat">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#propdef-border-image-repeat">https://drafts.csswg.org/css-backgrounds-3/#propdef-border-image-repeat</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-border-image-repeat">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-background-repeat-round">
   <a href="https://drafts.csswg.org/css-backgrounds-3/#valdef-background-repeat-round">https://drafts.csswg.org/css-backgrounds-3/#valdef-background-repeat-round</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-background-repeat-round">4.4. Examples of CSS Object Sizing</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-valdef-stroke-align-center">
   <a href="https://drafts.fxtf.org/fill-stroke-3/#valdef-stroke-align-center">https://drafts.fxtf.org/fill-stroke-3/#valdef-stroke-align-center</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-stroke-align-center">3.2.1. radial-gradient() Syntax</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-the-iframe-element">
   <a href="https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element">https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-the-iframe-element">4.1. Object-Sizing Terminology</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-the-img-element">
   <a href="https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element">https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-the-img-element">4.2. CSS⇋Object Negotiation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-attr-img-src">
   <a href="https://html.spec.whatwg.org/multipage/embedded-content.html#attr-img-src">https://html.spec.whatwg.org/multipage/embedded-content.html#attr-img-src</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-attr-img-src">4.2. CSS⇋Object Negotiation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-target-pseudo">
   <a href="https://drafts.csswg.org/selectors-4/#target-pseudo">https://drafts.csswg.org/selectors-4/#target-pseudo</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-target-pseudo">2.1.1. Ambiguous Reference-or-Image URLs</a>
   </ul>
  </aside>
  <h3 class="no-num no-ref heading settled" id="index-defined-elsewhere"><span class="content">Terms defined by reference</span><a class="self-link" href="#index-defined-elsewhere"></a></h3>
  <ul class="index">
   <li>
    <a data-link-type="biblio">[css-cascade-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-computed-value" style="color:initial">computed value</span>
     <li><span class="dfn-paneled" id="term-for-valdef-all-initial" style="color:initial">initial</span>
     <li><span class="dfn-paneled" id="term-for-specified-value" style="color:initial">specified value</span>
     <li><span class="dfn-paneled" id="term-for-used-value" style="color:initial">used value</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-color-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-valuea-def-color" style="color:initial">&lt;color></span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-color-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-valdef-color-transparent" style="color:initial">transparent</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-content-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-content" style="color:initial">content</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-images-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-typedef-color-stop" style="color:initial">&lt;color-stop></span>
     <li><span class="dfn-paneled" id="term-for-funcdef-image" style="color:initial">image()</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-lists-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-list-style-image" style="color:initial">list-style-image</span>
     <li><span class="dfn-paneled" id="term-for-propdef-list-style-type" style="color:initial">list-style-type</span>
     <li><span class="dfn-paneled" id="term-for-valdef-list-style-type-none" style="color:initial">none</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-masking-1]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-elementdef-mask" style="color:initial">mask</span>
     <li><span class="dfn-paneled" id="term-for-propdef-mask-image" style="color:initial">mask-image</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-ui-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-cursor" style="color:initial">cursor</span>
    </ul>
   <li>
    <a data-link-type="biblio">[CSS-VALUES-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-angle-value" style="color:initial">&lt;angle></span>
     <li><span class="dfn-paneled" id="term-for-length-value" style="color:initial">&lt;length></span>
     <li><span class="dfn-paneled" id="term-for-resolution-value" style="color:initial">&lt;resolution></span>
     <li><span class="dfn-paneled" id="term-for-url-value" style="color:initial">&lt;url></span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-values-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-mult-comma" style="color:initial">#</span>
     <li><span class="dfn-paneled" id="term-for-comb-all" style="color:initial">&amp;&amp;</span>
     <li><span class="dfn-paneled" id="term-for-comb-comma" style="color:initial">,</span>
     <li><span class="dfn-paneled" id="term-for-typedef-length-percentage" style="color:initial">&lt;length-percentage></span>
     <li><span class="dfn-paneled" id="term-for-typedef-position" style="color:initial">&lt;position></span>
     <li><span class="dfn-paneled" id="term-for-mult-opt" style="color:initial">?</span>
     <li><span class="dfn-paneled" id="term-for-funcdef-url" style="color:initial">url()</span>
     <li><span class="dfn-paneled" id="term-for-comb-one" style="color:initial">|</span>
     <li><span class="dfn-paneled" id="term-for-comb-any" style="color:initial">||</span>
    </ul>
   <li>
    <a data-link-type="biblio">[css-writing-modes-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-valdef-direction-ltr" style="color:initial">ltr</span>
     <li><span class="dfn-paneled" id="term-for-valdef-direction-rtl" style="color:initial">rtl</span>
    </ul>
   <li>
    <a data-link-type="biblio">[CSS2]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-height" style="color:initial">height</span>
     <li><span class="dfn-paneled" id="term-for-propdef-width" style="color:initial">width</span>
    </ul>
   <li>
    <a data-link-type="biblio">[CSS3BG]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-propdef-background" style="color:initial">background</span>
     <li><span class="dfn-paneled" id="term-for-propdef-background-image" style="color:initial">background-image</span>
     <li><span class="dfn-paneled" id="term-for-propdef-background-position" style="color:initial">background-position</span>
     <li><span class="dfn-paneled" id="term-for-propdef-background-repeat" style="color:initial">background-repeat</span>
     <li><span class="dfn-paneled" id="term-for-propdef-background-size" style="color:initial">background-size</span>
     <li><span class="dfn-paneled" id="term-for-propdef-border-image" style="color:initial">border-image</span>
     <li><span class="dfn-paneled" id="term-for-propdef-border-image-repeat" style="color:initial">border-image-repeat</span>
     <li><span class="dfn-paneled" id="term-for-valdef-background-repeat-round" style="color:initial">round</span>
    </ul>
   <li>
    <a data-link-type="biblio">[fill-stroke-3]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-valdef-stroke-align-center" style="color:initial">center</span>
    </ul>
   <li>
    <a data-link-type="biblio">[HTML]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-the-iframe-element" style="color:initial">iframe</span>
     <li><span class="dfn-paneled" id="term-for-the-img-element" style="color:initial">img</span>
     <li><span class="dfn-paneled" id="term-for-attr-img-src" style="color:initial">src</span>
    </ul>
   <li>
    <a data-link-type="biblio">[selectors-4]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-target-pseudo" style="color:initial">:target</span>
    </ul>
  </ul>
  <h2 class="no-num no-ref heading settled" id="references"><span class="content">References</span><a class="self-link" href="#references"></a></h2>
  <h3 class="no-num no-ref heading settled" id="normative"><span class="content">Normative References</span><a class="self-link" href="#normative"></a></h3>
  <dl>
   <dt id="biblio-css-cascade-4">[CSS-CASCADE-4]
   <dd>Elika Etemad; Tab Atkins Jr.. <a href="https://www.w3.org/TR/css-cascade-4/">CSS Cascading and Inheritance Level 4</a>. 28 August 2018. CR. URL: <a href="https://www.w3.org/TR/css-cascade-4/">https://www.w3.org/TR/css-cascade-4/</a>
   <dt id="biblio-css-color-3">[CSS-COLOR-3]
   <dd>Tantek Çelik; Chris Lilley; David Baron. <a href="https://www.w3.org/TR/css-color-3/">CSS Color Module Level 3</a>. 19 June 2018. REC. URL: <a href="https://www.w3.org/TR/css-color-3/">https://www.w3.org/TR/css-color-3/</a>
   <dt id="biblio-css-color-4">[CSS-COLOR-4]
   <dd>Tab Atkins Jr.; Chris Lilley. <a href="https://www.w3.org/TR/css-color-4/">CSS Color Module Level 4</a>. 5 March 2019. WD. URL: <a href="https://www.w3.org/TR/css-color-4/">https://www.w3.org/TR/css-color-4/</a>
   <dt id="biblio-css-content-3">[CSS-CONTENT-3]
   <dd>Elika Etemad; Dave Cramer. <a href="https://www.w3.org/TR/css-content-3/">CSS Generated Content Module Level 3</a>. 2 June 2016. WD. URL: <a href="https://www.w3.org/TR/css-content-3/">https://www.w3.org/TR/css-content-3/</a>
   <dt id="biblio-css-images-4">[CSS-IMAGES-4]
   <dd>Tab Atkins Jr.; Elika Etemad; Lea Verou. <a href="https://www.w3.org/TR/css-images-4/">CSS Image Values and Replaced Content Module Level 4</a>. 13 April 2017. WD. URL: <a href="https://www.w3.org/TR/css-images-4/">https://www.w3.org/TR/css-images-4/</a>
   <dt id="biblio-css-lists-3">[CSS-LISTS-3]
   <dd>Elika Etemad; Tab Atkins Jr.. <a href="https://www.w3.org/TR/css-lists-3/">CSS Lists Module Level 3</a>. 25 April 2019. WD. URL: <a href="https://www.w3.org/TR/css-lists-3/">https://www.w3.org/TR/css-lists-3/</a>
   <dt id="biblio-css-masking-1">[CSS-MASKING-1]
   <dd>Dirk Schulze; Brian Birtles; Tab Atkins Jr.. <a href="https://www.w3.org/TR/css-masking-1/">CSS Masking Module Level 1</a>. 26 August 2014. CR. URL: <a href="https://www.w3.org/TR/css-masking-1/">https://www.w3.org/TR/css-masking-1/</a>
   <dt id="biblio-css-ui-4">[CSS-UI-4]
   <dd>Florian Rivoal. <a href="https://www.w3.org/TR/css-ui-4/">CSS Basic User Interface Module Level 4</a>. 22 December 2017. WD. URL: <a href="https://www.w3.org/TR/css-ui-4/">https://www.w3.org/TR/css-ui-4/</a>
   <dt id="biblio-css-values-3">[CSS-VALUES-3]
   <dd>Tab Atkins Jr.; Elika Etemad. <a href="https://www.w3.org/TR/css-values-3/">CSS Values and Units Module Level 3</a>. 31 January 2019. CR. URL: <a href="https://www.w3.org/TR/css-values-3/">https://www.w3.org/TR/css-values-3/</a>
   <dt id="biblio-css-values-4">[CSS-VALUES-4]
   <dd>Tab Atkins Jr.; Elika Etemad. <a href="https://www.w3.org/TR/css-values-4/">CSS Values and Units Module Level 4</a>. 31 January 2019. WD. URL: <a href="https://www.w3.org/TR/css-values-4/">https://www.w3.org/TR/css-values-4/</a>
   <dt id="biblio-css-writing-modes-4">[CSS-WRITING-MODES-4]
   <dd>Elika Etemad; Koji Ishii. <a href="https://www.w3.org/TR/css-writing-modes-4/">CSS Writing Modes Level 4</a>. 24 May 2018. CR. URL: <a href="https://www.w3.org/TR/css-writing-modes-4/">https://www.w3.org/TR/css-writing-modes-4/</a>
   <dt id="biblio-css2">[CSS2]
   <dd>Bert Bos; et al. <a href="https://www.w3.org/TR/CSS2/">Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification</a>. 7 June 2011. REC. URL: <a href="https://www.w3.org/TR/CSS2/">https://www.w3.org/TR/CSS2/</a>
   <dt id="biblio-css3bg">[CSS3BG]
   <dd>Bert Bos; Elika Etemad; Brad Kemper. <a href="https://www.w3.org/TR/css-backgrounds-3/">CSS Backgrounds and Borders Module Level 3</a>. 17 October 2017. CR. URL: <a href="https://www.w3.org/TR/css-backgrounds-3/">https://www.w3.org/TR/css-backgrounds-3/</a>
   <dt id="biblio-fill-stroke-3">[FILL-STROKE-3]
   <dd>Elika Etemad; Tab Atkins Jr.. <a href="https://www.w3.org/TR/fill-stroke-3/">CSS Fill and Stroke Module Level 3</a>. 13 April 2017. WD. URL: <a href="https://www.w3.org/TR/fill-stroke-3/">https://www.w3.org/TR/fill-stroke-3/</a>
   <dt id="biblio-html">[HTML]
   <dd>Anne van Kesteren; et al. <a href="https://html.spec.whatwg.org/multipage/">HTML Standard</a>. Living Standard. URL: <a href="https://html.spec.whatwg.org/multipage/">https://html.spec.whatwg.org/multipage/</a>
   <dt id="biblio-rfc2119">[RFC2119]
   <dd>S. Bradner. <a href="https://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>. March 1997. Best Current Practice. URL: <a href="https://tools.ietf.org/html/rfc2119">https://tools.ietf.org/html/rfc2119</a>
  </dl>
  <h3 class="no-num no-ref heading settled" id="informative"><span class="content">Informative References</span><a class="self-link" href="#informative"></a></h3>
  <dl>
   <dt id="biblio-css-transforms-1">[CSS-TRANSFORMS-1]
   <dd>Simon Fraser; et al. <a href="https://www.w3.org/TR/css-transforms-1/">CSS Transforms Module Level 1</a>. 14 February 2019. CR. URL: <a href="https://www.w3.org/TR/css-transforms-1/">https://www.w3.org/TR/css-transforms-1/</a>
   <dt id="biblio-css3page">[CSS3PAGE]
   <dd>Elika Etemad; Simon Sapin. <a href="https://www.w3.org/TR/css-page-3/">CSS Paged Media Module Level 3</a>. 18 October 2018. WD. URL: <a href="https://www.w3.org/TR/css-page-3/">https://www.w3.org/TR/css-page-3/</a>
   <dt id="biblio-cssom">[CSSOM]
   <dd>Simon Pieters; Glenn Adams. <a href="https://www.w3.org/TR/cssom-1/">CSS Object Model (CSSOM)</a>. 17 March 2016. WD. URL: <a href="https://www.w3.org/TR/cssom-1/">https://www.w3.org/TR/cssom-1/</a>
   <dt id="biblio-selectors-4">[SELECTORS-4]
   <dd>Elika Etemad; Tab Atkins Jr.. <a href="https://www.w3.org/TR/selectors-4/">Selectors Level 4</a>. 21 November 2018. WD. URL: <a href="https://www.w3.org/TR/selectors-4/">https://www.w3.org/TR/selectors-4/</a>
   <dt id="biblio-smil10">[SMIL10]
   <dd>Philipp Hoschka. <a href="https://www.w3.org/TR/1998/REC-smil-19980615/">Synchronized Multimedia Integration Language (SMIL) 1.0 Specification</a>. 15 June 1998. REC. URL: <a href="https://www.w3.org/TR/1998/REC-smil-19980615/">https://www.w3.org/TR/1998/REC-smil-19980615/</a>
   <dt id="biblio-svg11">[SVG11]
   <dd>Erik Dahlström; et al. <a href="https://www.w3.org/TR/SVG11/">Scalable Vector Graphics (SVG) 1.1 (Second Edition)</a>. 16 August 2011. REC. URL: <a href="https://www.w3.org/TR/SVG11/">https://www.w3.org/TR/SVG11/</a>
  </dl>
  <h2 class="no-num no-ref heading settled" id="property-index"><span class="content">Property Index</span><a class="self-link" href="#property-index"></a></h2>
  <div class="big-element-wrapper">
   <table class="index">
    <thead>
     <tr>
      <th scope="col">Name
      <th scope="col">Value
      <th scope="col">Initial
      <th scope="col">Applies to
      <th scope="col">Inh.
      <th scope="col">%ages
      <th scope="col">Anim­ation type
      <th scope="col">Canonical order
      <th scope="col">Com­puted value
    <tbody>
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-image-orientation" id="ref-for-propdef-image-orientation⑧">image-orientation</a>
      <td>from-image | none | &lt;angle> | [ &lt;angle>? flip ]
      <td>from-image
      <td>all elements
      <td>yes
      <td>n/a
      <td>discrete
      <td>per grammar
      <td>the specified keyword, or an &lt;angle>, rounded and normalized (see text), plus optionally a flip keyword
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-image-rendering" id="ref-for-propdef-image-rendering⑦">image-rendering</a>
      <td>auto | smooth | high-quality | crisp-edges | pixelated
      <td>auto
      <td>all elements
      <td>yes
      <td>n/a
      <td>discrete
      <td>per grammar
      <td>specified keyword
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-object-fit" id="ref-for-propdef-object-fit⑧">object-fit</a>
      <td>fill | contain | cover | none | scale-down
      <td>fill
      <td>replaced elements
      <td>no
      <td>n/a
      <td>discrete
      <td>per grammar
      <td>specified keyword
     <tr>
      <th scope="row"><a class="css" data-link-type="property" href="#propdef-object-position" id="ref-for-propdef-object-position⑥">object-position</a>
      <td>&lt;position>
      <td>50% 50%
      <td>replaced elements
      <td>no
      <td>refer to width and height of element itself
      <td>as for background-position
      <td>the horizontal component of the &lt;position>, followed by the vertical component
      <td>as for background-position
   </table>
  </div>
  <h2 class="no-num no-ref heading settled" id="issues-index"><span class="content">Issues Index</span><a class="self-link" href="#issues-index"></a></h2>
  <div style="counter-reset:issue">
   <div class="issue"> Add a visual example of a color hint being used.<a href="#issue-7a141efc"> ↵ </a></div>
  </div>
  <aside class="dfn-panel" data-for="typedef-image">
   <b><a href="#typedef-image">#typedef-image</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-image④">1.1. Module Interactions</a> <a href="#ref-for-typedef-image⑤">(2)</a> <a href="#ref-for-typedef-image⑥">(3)</a> <a href="#ref-for-typedef-image⑦">(4)</a>
    <li><a href="#ref-for-typedef-image⑧">2. Image Values: the &lt;image> type</a> <a href="#ref-for-typedef-image⑨">(2)</a> <a href="#ref-for-typedef-image①⓪">(3)</a> <a href="#ref-for-typedef-image①①">(4)</a>
    <li><a href="#ref-for-typedef-image①②">2.1.1. Ambiguous Reference-or-Image URLs</a> <a href="#ref-for-typedef-image①③">(2)</a> <a href="#ref-for-typedef-image①④">(3)</a>
    <li><a href="#ref-for-typedef-image①⑤">3. Gradients</a>
    <li><a href="#ref-for-typedef-image①⑥">6. Interpolation</a>
    <li><a href="#ref-for-typedef-image①⑦"> Changes Since the 17 April 2012 Candidate Recommendation</a> <a href="#ref-for-typedef-image①⑧">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="invalid-image">
   <b><a href="#invalid-image">#invalid-image</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-invalid-image">2. Image Values: the &lt;image> type</a> <a href="#ref-for-invalid-image①">(2)</a> <a href="#ref-for-invalid-image②">(3)</a>
    <li><a href="#ref-for-invalid-image③">2.1. Image References: the url() notation</a>
    <li><a href="#ref-for-invalid-image④"> Changes Since Last Call</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="loading-image">
   <b><a href="#loading-image">#loading-image</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-loading-image">2. Image Values: the &lt;image> type</a> <a href="#ref-for-loading-image①">(2)</a> <a href="#ref-for-loading-image②">(3)</a> <a href="#ref-for-loading-image③">(4)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="css-ambiguous-image-url">
   <b><a href="#css-ambiguous-image-url">#css-ambiguous-image-url</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-css-ambiguous-image-url">2.1.1. Ambiguous Reference-or-Image URLs</a> <a href="#ref-for-css-ambiguous-image-url①">(2)</a> <a href="#ref-for-css-ambiguous-image-url②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="gradient-function">
   <b><a href="#gradient-function">#gradient-function</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-gradient-function">3.4. Defining Gradient Color</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="typedef-gradient">
   <b><a href="#typedef-gradient">#typedef-gradient</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-gradient">2. Image Values: the &lt;image> type</a>
    <li><a href="#ref-for-typedef-gradient①">3. Gradients</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="gradient-box">
   <b><a href="#gradient-box">#gradient-box</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-gradient-box">3. Gradients</a> <a href="#ref-for-gradient-box①">(2)</a>
    <li><a href="#ref-for-gradient-box②">3.1.1. linear-gradient() syntax</a> <a href="#ref-for-gradient-box③">(2)</a> <a href="#ref-for-gradient-box④">(3)</a>
    <li><a href="#ref-for-gradient-box⑤">3.2. Radial Gradients: the radial-gradient() notation</a>
    <li><a href="#ref-for-gradient-box⑥">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-gradient-box⑦">(2)</a> <a href="#ref-for-gradient-box⑧">(3)</a> <a href="#ref-for-gradient-box⑨">(4)</a> <a href="#ref-for-gradient-box①⓪">(5)</a>
    <li><a href="#ref-for-gradient-box①①">3.2.3. Degenerate Radial Gradients</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="starting-point">
   <b><a href="#starting-point">#starting-point</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-starting-point">3.1.1. linear-gradient() syntax</a> <a href="#ref-for-starting-point①">(2)</a>
    <li><a href="#ref-for-starting-point②">3.2.2. Placing Color Stops</a>
    <li><a href="#ref-for-starting-point③">3.4. Defining Gradient Color</a>
    <li><a href="#ref-for-starting-point④">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-starting-point⑤">(2)</a> <a href="#ref-for-starting-point⑥">(3)</a> <a href="#ref-for-starting-point⑦">(4)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="ending-point">
   <b><a href="#ending-point">#ending-point</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-ending-point">3.1.1. linear-gradient() syntax</a> <a href="#ref-for-ending-point①">(2)</a>
    <li><a href="#ref-for-ending-point②">3.2.2. Placing Color Stops</a>
    <li><a href="#ref-for-ending-point③">3.4. Defining Gradient Color</a>
    <li><a href="#ref-for-ending-point④">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-ending-point⑤">(2)</a> <a href="#ref-for-ending-point⑥">(3)</a> <a href="#ref-for-ending-point⑦">(4)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="gradient-line">
   <b><a href="#gradient-line">#gradient-line</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-gradient-line">3. Gradients</a>
    <li><a href="#ref-for-gradient-line①">3.1. Linear Gradients: the linear-gradient() notation</a>
    <li><a href="#ref-for-gradient-line②">3.1.1. linear-gradient() syntax</a> <a href="#ref-for-gradient-line③">(2)</a> <a href="#ref-for-gradient-line④">(3)</a> <a href="#ref-for-gradient-line⑤">(4)</a> <a href="#ref-for-gradient-line⑥">(5)</a> <a href="#ref-for-gradient-line⑦">(6)</a> <a href="#ref-for-gradient-line⑧">(7)</a> <a href="#ref-for-gradient-line⑨">(8)</a> <a href="#ref-for-gradient-line①⓪">(9)</a> <a href="#ref-for-gradient-line①①">(10)</a> <a href="#ref-for-gradient-line①②">(11)</a> <a href="#ref-for-gradient-line①③">(12)</a>
    <li><a href="#ref-for-gradient-line①④">3.1.2. Linear Gradient Examples</a>
    <li><a href="#ref-for-gradient-line①⑤">3.2.2. Placing Color Stops</a> <a href="#ref-for-gradient-line①⑥">(2)</a> <a href="#ref-for-gradient-line①⑦">(3)</a> <a href="#ref-for-gradient-line①⑧">(4)</a> <a href="#ref-for-gradient-line①⑨">(5)</a> <a href="#ref-for-gradient-line②⓪">(6)</a> <a href="#ref-for-gradient-line②①">(7)</a>
    <li><a href="#ref-for-gradient-line②②">3.4. Defining Gradient Color</a> <a href="#ref-for-gradient-line②③">(2)</a> <a href="#ref-for-gradient-line②④">(3)</a>
    <li><a href="#ref-for-gradient-line②⑤">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-gradient-line②⑥">(2)</a> <a href="#ref-for-gradient-line②⑦">(3)</a> <a href="#ref-for-gradient-line②⑧">(4)</a>
    <li><a href="#ref-for-gradient-line②⑨">3.4.2. 
Coloring the Gradient Line</a> <a href="#ref-for-gradient-line③⓪">(2)</a> <a href="#ref-for-gradient-line③①">(3)</a> <a href="#ref-for-gradient-line③②">(4)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="funcdef-linear-gradient">
   <b><a href="#funcdef-linear-gradient">#funcdef-linear-gradient</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-funcdef-linear-gradient">3. Gradients</a>
    <li><a href="#ref-for-funcdef-linear-gradient①">3.1. Linear Gradients: the linear-gradient() notation</a>
    <li><a href="#ref-for-funcdef-linear-gradient②">3.1.2. Linear Gradient Examples</a>
    <li><a href="#ref-for-funcdef-linear-gradient③">3.2. Radial Gradients: the radial-gradient() notation</a>
    <li><a href="#ref-for-funcdef-linear-gradient④">3.3. Repeating Gradients: the repeating-linear-gradient() and repeating-radial-gradient() notations</a>
    <li><a href="#ref-for-funcdef-linear-gradient⑤"> Changes Since the 17 April 2012 Candidate Recommendation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="typedef-side-or-corner">
   <b><a href="#typedef-side-or-corner">#typedef-side-or-corner</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-side-or-corner">3.1.1. linear-gradient() syntax</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="ending-shape">
   <b><a href="#ending-shape">#ending-shape</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-ending-shape">3.2. Radial Gradients: the radial-gradient() notation</a>
    <li><a href="#ref-for-ending-shape①">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-ending-shape②">(2)</a> <a href="#ref-for-ending-shape③">(3)</a> <a href="#ref-for-ending-shape④">(4)</a> <a href="#ref-for-ending-shape⑤">(5)</a> <a href="#ref-for-ending-shape⑥">(6)</a> <a href="#ref-for-ending-shape⑦">(7)</a> <a href="#ref-for-ending-shape⑧">(8)</a> <a href="#ref-for-ending-shape⑨">(9)</a>
    <li><a href="#ref-for-ending-shape①⓪">3.2.2. Placing Color Stops</a>
    <li><a href="#ref-for-ending-shape①①">3.2.3. Degenerate Radial Gradients</a> <a href="#ref-for-ending-shape①②">(2)</a> <a href="#ref-for-ending-shape①③">(3)</a> <a href="#ref-for-ending-shape①④">(4)</a> <a href="#ref-for-ending-shape①⑤">(5)</a> <a href="#ref-for-ending-shape①⑥">(6)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="funcdef-radial-gradient">
   <b><a href="#funcdef-radial-gradient">#funcdef-radial-gradient</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-funcdef-radial-gradient">3. Gradients</a>
    <li><a href="#ref-for-funcdef-radial-gradient①">3.2. Radial Gradients: the radial-gradient() notation</a>
    <li><a href="#ref-for-funcdef-radial-gradient②">3.3. Repeating Gradients: the repeating-linear-gradient() and repeating-radial-gradient() notations</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="radial-gradient-gradient-center">
   <b><a href="#radial-gradient-gradient-center">#radial-gradient-gradient-center</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-radial-gradient-gradient-center">3.2. Radial Gradients: the radial-gradient() notation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-ending-shape-circle">
   <b><a href="#valdef-ending-shape-circle">#valdef-ending-shape-circle</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-ending-shape-circle">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-valdef-ending-shape-circle①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-ending-shape-ellipse">
   <b><a href="#valdef-ending-shape-ellipse">#valdef-ending-shape-ellipse</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-ending-shape-ellipse">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-valdef-ending-shape-ellipse①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="typedef-size">
   <b><a href="#typedef-size">#typedef-size</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-size">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-typedef-size①">(2)</a> <a href="#ref-for-typedef-size②">(3)</a> <a href="#ref-for-typedef-size③">(4)</a> <a href="#ref-for-typedef-size④">(5)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-size-closest-side">
   <b><a href="#valdef-size-closest-side">#valdef-size-closest-side</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-size-closest-side">3.2.1. radial-gradient() Syntax</a> <a href="#ref-for-valdef-size-closest-side①">(2)</a>
    <li><a href="#ref-for-valdef-size-closest-side②">3.2.3. Degenerate Radial Gradients</a>
    <li><a href="#ref-for-valdef-size-closest-side③">3.2.4. Radial Gradient Examples</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-size-farthest-side">
   <b><a href="#valdef-size-farthest-side">#valdef-size-farthest-side</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-size-farthest-side">3.2.1. radial-gradient() Syntax</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-size-closest-corner">
   <b><a href="#valdef-size-closest-corner">#valdef-size-closest-corner</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-size-closest-corner">3.2.1. radial-gradient() Syntax</a>
    <li><a href="#ref-for-valdef-size-closest-corner①">3.2.3. Degenerate Radial Gradients</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-size-farthest-corner">
   <b><a href="#valdef-size-farthest-corner">#valdef-size-farthest-corner</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-size-farthest-corner">3.2.1. radial-gradient() Syntax</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="typedef-extent-keyword">
   <b><a href="#typedef-extent-keyword">#typedef-extent-keyword</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-extent-keyword">3.2.1. radial-gradient() Syntax</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="funcdef-repeating-linear-gradient">
   <b><a href="#funcdef-repeating-linear-gradient">#funcdef-repeating-linear-gradient</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-funcdef-repeating-linear-gradient">3. Gradients</a>
    <li><a href="#ref-for-funcdef-repeating-linear-gradient①">3.3. Repeating Gradients: the repeating-linear-gradient() and repeating-radial-gradient() notations</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="funcdef-repeating-radial-gradient">
   <b><a href="#funcdef-repeating-radial-gradient">#funcdef-repeating-radial-gradient</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-funcdef-repeating-radial-gradient">3. Gradients</a>
    <li><a href="#ref-for-funcdef-repeating-radial-gradient①">3.3. Repeating Gradients: the repeating-linear-gradient() and repeating-radial-gradient() notations</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="gradient-average-color">
   <b><a href="#gradient-average-color">#gradient-average-color</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-gradient-average-color">3.3. Repeating Gradients: the repeating-linear-gradient() and repeating-radial-gradient() notations</a> <a href="#ref-for-gradient-average-color①">(2)</a> <a href="#ref-for-gradient-average-color②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="color-stop">
   <b><a href="#color-stop">#color-stop</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-color-stop">3.4. Defining Gradient Color</a>
    <li><a href="#ref-for-color-stop①">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-color-stop②">(2)</a> <a href="#ref-for-color-stop③">(3)</a> <a href="#ref-for-color-stop④">(4)</a> <a href="#ref-for-color-stop⑤">(5)</a>
    <li><a href="#ref-for-color-stop⑥">3.4.2. 
Coloring the Gradient Line</a> <a href="#ref-for-color-stop⑦">(2)</a> <a href="#ref-for-color-stop⑧">(3)</a> <a href="#ref-for-color-stop⑨">(4)</a> <a href="#ref-for-color-stop①⓪">(5)</a> <a href="#ref-for-color-stop①①">(6)</a> <a href="#ref-for-color-stop①②">(7)</a> <a href="#ref-for-color-stop①③">(8)</a> <a href="#ref-for-color-stop①④">(9)</a> <a href="#ref-for-color-stop①⑤">(10)</a> <a href="#ref-for-color-stop①⑥">(11)</a> <a href="#ref-for-color-stop①⑦">(12)</a> <a href="#ref-for-color-stop①⑧">(13)</a> <a href="#ref-for-color-stop①⑨">(14)</a> <a href="#ref-for-color-stop②⓪">(15)</a> <a href="#ref-for-color-stop②①">(16)</a>
    <li><a href="#ref-for-color-stop②②">3.4.3. 
Color Stop “Fixup”</a> <a href="#ref-for-color-stop②③">(2)</a> <a href="#ref-for-color-stop②④">(3)</a> <a href="#ref-for-color-stop②⑤">(4)</a> <a href="#ref-for-color-stop②⑥">(5)</a> <a href="#ref-for-color-stop②⑦">(6)</a> <a href="#ref-for-color-stop②⑧">(7)</a> <a href="#ref-for-color-stop②⑨">(8)</a> <a href="#ref-for-color-stop③⓪">(9)</a> <a href="#ref-for-color-stop③①">(10)</a> <a href="#ref-for-color-stop③②">(11)</a> <a href="#ref-for-color-stop③③">(12)</a> <a href="#ref-for-color-stop③④">(13)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="color-transition-hint">
   <b><a href="#color-transition-hint">#color-transition-hint</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-color-transition-hint">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-color-transition-hint①">(2)</a> <a href="#ref-for-color-transition-hint②">(3)</a>
    <li><a href="#ref-for-color-transition-hint③">3.4.2. 
Coloring the Gradient Line</a> <a href="#ref-for-color-transition-hint④">(2)</a> <a href="#ref-for-color-transition-hint⑤">(3)</a>
    <li><a href="#ref-for-color-transition-hint⑥">3.4.3. 
Color Stop “Fixup”</a> <a href="#ref-for-color-transition-hint⑦">(2)</a> <a href="#ref-for-color-transition-hint⑧">(3)</a> <a href="#ref-for-color-transition-hint⑨">(4)</a>
    <li><a href="#ref-for-color-transition-hint①⓪"> Changes Since the 17 April 2012 Candidate Recommendation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="color-stop-list">
   <b><a href="#color-stop-list">#color-stop-list</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-color-stop-list">3.4.1. 
Color Stop Lists</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="typedef-color-stop-list">
   <b><a href="#typedef-color-stop-list">#typedef-color-stop-list</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-color-stop-list">3.1.1. linear-gradient() syntax</a>
    <li><a href="#ref-for-typedef-color-stop-list①">3.2.1. radial-gradient() Syntax</a>
    <li><a href="#ref-for-typedef-color-stop-list②"> Changes Since the 17 April 2012 Candidate Recommendation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="typedef-linear-color-stop">
   <b><a href="#typedef-linear-color-stop">#typedef-linear-color-stop</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-linear-color-stop">3.4.1. 
Color Stop Lists</a> <a href="#ref-for-typedef-linear-color-stop①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="typedef-linear-color-hint">
   <b><a href="#typedef-linear-color-hint">#typedef-linear-color-hint</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-typedef-linear-color-hint">3.4.1. 
Color Stop Lists</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="objects">
   <b><a href="#objects">#objects</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-objects">4.1. Object-Sizing Terminology</a> <a href="#ref-for-objects①">(2)</a> <a href="#ref-for-objects②">(3)</a> <a href="#ref-for-objects③">(4)</a> <a href="#ref-for-objects④">(5)</a> <a href="#ref-for-objects⑤">(6)</a>
    <li><a href="#ref-for-objects⑥">4.2. CSS⇋Object Negotiation</a> <a href="#ref-for-objects⑦">(2)</a> <a href="#ref-for-objects⑧">(3)</a> <a href="#ref-for-objects⑨">(4)</a> <a href="#ref-for-objects①⓪">(5)</a> <a href="#ref-for-objects①①">(6)</a> <a href="#ref-for-objects①②">(7)</a> <a href="#ref-for-objects①③">(8)</a> <a href="#ref-for-objects①④">(9)</a>
    <li><a href="#ref-for-objects①⑤">4.3. Concrete Object Size Resolution</a> <a href="#ref-for-objects①⑥">(2)</a>
    <li><a href="#ref-for-objects①⑦">4.3.1. Default Sizing Algorithm</a> <a href="#ref-for-objects①⑧">(2)</a> <a href="#ref-for-objects①⑨">(3)</a> <a href="#ref-for-objects②⓪">(4)</a> <a href="#ref-for-objects②①">(5)</a> <a href="#ref-for-objects②②">(6)</a>
    <li><a href="#ref-for-objects②③">4.3.2. Cover and Contain Constraint Sizing</a> <a href="#ref-for-objects②④">(2)</a> <a href="#ref-for-objects②⑤">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="intrinsic-dimensions">
   <b><a href="#intrinsic-dimensions">#intrinsic-dimensions</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-intrinsic-dimensions">2. Image Values: the &lt;image> type</a>
    <li><a href="#ref-for-intrinsic-dimensions①">3. Gradients</a>
    <li><a href="#ref-for-intrinsic-dimensions②">4.1. Object-Sizing Terminology</a> <a href="#ref-for-intrinsic-dimensions③">(2)</a>
    <li><a href="#ref-for-intrinsic-dimensions④">4.2. CSS⇋Object Negotiation</a> <a href="#ref-for-intrinsic-dimensions⑤">(2)</a> <a href="#ref-for-intrinsic-dimensions⑥">(3)</a>
    <li><a href="#ref-for-intrinsic-dimensions⑦">4.3.1. Default Sizing Algorithm</a> <a href="#ref-for-intrinsic-dimensions⑧">(2)</a> <a href="#ref-for-intrinsic-dimensions⑨">(3)</a> <a href="#ref-for-intrinsic-dimensions①⓪">(4)</a>
    <li><a href="#ref-for-intrinsic-dimensions"> Changes Since Last Call</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="intrinsic-height">
   <b><a href="#intrinsic-height">#intrinsic-height</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-intrinsic-height">4.1. Object-Sizing Terminology</a> <a href="#ref-for-intrinsic-height①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="intrinsic-width">
   <b><a href="#intrinsic-width">#intrinsic-width</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-intrinsic-width">4.1. Object-Sizing Terminology</a> <a href="#ref-for-intrinsic-width①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="intrinsic-aspect-ratio">
   <b><a href="#intrinsic-aspect-ratio">#intrinsic-aspect-ratio</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-intrinsic-aspect-ratio">4.1. Object-Sizing Terminology</a> <a href="#ref-for-intrinsic-aspect-ratio①">(2)</a>
    <li><a href="#ref-for-intrinsic-aspect-ratio②">4.3.1. Default Sizing Algorithm</a> <a href="#ref-for-intrinsic-aspect-ratio③">(2)</a>
    <li><a href="#ref-for-intrinsic-aspect-ratio④">4.3.2. Cover and Contain Constraint Sizing</a> <a href="#ref-for-intrinsic-aspect-ratio⑤">(2)</a> <a href="#ref-for-intrinsic-aspect-ratio⑥">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="specified-size">
   <b><a href="#specified-size">#specified-size</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-specified-size">4.1. Object-Sizing Terminology</a> <a href="#ref-for-specified-size①">(2)</a>
    <li><a href="#ref-for-specified-size②">4.2. CSS⇋Object Negotiation</a>
    <li><a href="#ref-for-specified-size③">4.3.1. Default Sizing Algorithm</a> <a href="#ref-for-specified-size④">(2)</a> <a href="#ref-for-specified-size⑤">(3)</a> <a href="#ref-for-specified-size⑥">(4)</a> <a href="#ref-for-specified-size⑦">(5)</a>
    <li><a href="#ref-for-specified-size⑧">4.4. Examples of CSS Object Sizing</a> <a href="#ref-for-specified-size⑨">(2)</a> <a href="#ref-for-specified-size①⓪">(3)</a> <a href="#ref-for-specified-size①①">(4)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="concrete-object-size">
   <b><a href="#concrete-object-size">#concrete-object-size</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-concrete-object-size">3. Gradients</a>
    <li><a href="#ref-for-concrete-object-size①">4.1. Object-Sizing Terminology</a> <a href="#ref-for-concrete-object-size②">(2)</a>
    <li><a href="#ref-for-concrete-object-size③">4.2. CSS⇋Object Negotiation</a> <a href="#ref-for-concrete-object-size④">(2)</a> <a href="#ref-for-concrete-object-size⑤">(3)</a> <a href="#ref-for-concrete-object-size⑥">(4)</a> <a href="#ref-for-concrete-object-size⑦">(5)</a> <a href="#ref-for-concrete-object-size⑧">(6)</a>
    <li><a href="#ref-for-concrete-object-size⑨">4.3.1. Default Sizing Algorithm</a> <a href="#ref-for-concrete-object-size①⓪">(2)</a> <a href="#ref-for-concrete-object-size①①">(3)</a> <a href="#ref-for-concrete-object-size①②">(4)</a> <a href="#ref-for-concrete-object-size①③">(5)</a> <a href="#ref-for-concrete-object-size①④">(6)</a>
    <li><a href="#ref-for-concrete-object-size①⑤">4.3.2. Cover and Contain Constraint Sizing</a> <a href="#ref-for-concrete-object-size①⑥">(2)</a> <a href="#ref-for-concrete-object-size①⑦">(3)</a>
    <li><a href="#ref-for-concrete-object-size①⑧">4.4. Examples of CSS Object Sizing</a> <a href="#ref-for-concrete-object-size①⑨">(2)</a> <a href="#ref-for-concrete-object-size②⓪">(3)</a> <a href="#ref-for-concrete-object-size②①">(4)</a>
    <li><a href="#ref-for-concrete-object-size②②">4.5. Sizing Objects: the object-fit property</a> <a href="#ref-for-concrete-object-size②③">(2)</a> <a href="#ref-for-concrete-object-size②④">(3)</a> <a href="#ref-for-concrete-object-size②⑤">(4)</a> <a href="#ref-for-concrete-object-size②⑥">(5)</a> <a href="#ref-for-concrete-object-size②⑦">(6)</a>
    <li><a href="#ref-for-concrete-object-size②⑧">4.6. Positioning Objects: the object-position property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="default-object-size">
   <b><a href="#default-object-size">#default-object-size</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-default-object-size">3. Gradients</a>
    <li><a href="#ref-for-default-object-size①">4.1. Object-Sizing Terminology</a> <a href="#ref-for-default-object-size②">(2)</a> <a href="#ref-for-default-object-size③">(3)</a> <a href="#ref-for-default-object-size④">(4)</a>
    <li><a href="#ref-for-default-object-size⑤">4.2. CSS⇋Object Negotiation</a>
    <li><a href="#ref-for-default-object-size⑥">4.3.1. Default Sizing Algorithm</a> <a href="#ref-for-default-object-size⑦">(2)</a>
    <li><a href="#ref-for-default-object-size⑧">4.4. Examples of CSS Object Sizing</a> <a href="#ref-for-default-object-size⑨">(2)</a> <a href="#ref-for-default-object-size①⓪">(3)</a> <a href="#ref-for-default-object-size①①">(4)</a> <a href="#ref-for-default-object-size①②">(5)</a>
    <li><a href="#ref-for-default-object-size①③">4.5. Sizing Objects: the object-fit property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="object-size-negotiation">
   <b><a href="#object-size-negotiation">#object-size-negotiation</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-object-size-negotiation">4.5. Sizing Objects: the object-fit property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="default-sizing-algorithm">
   <b><a href="#default-sizing-algorithm">#default-sizing-algorithm</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-default-sizing-algorithm">4.3.1. Default Sizing Algorithm</a> <a href="#ref-for-default-sizing-algorithm①">(2)</a>
    <li><a href="#ref-for-default-sizing-algorithm②">4.4. Examples of CSS Object Sizing</a> <a href="#ref-for-default-sizing-algorithm③">(2)</a> <a href="#ref-for-default-sizing-algorithm④">(3)</a> <a href="#ref-for-default-sizing-algorithm⑤">(4)</a> <a href="#ref-for-default-sizing-algorithm⑥">(5)</a>
    <li><a href="#ref-for-default-sizing-algorithm⑦">4.5. Sizing Objects: the object-fit property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="contain-constraint">
   <b><a href="#contain-constraint">#contain-constraint</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-contain-constraint">4.1. Object-Sizing Terminology</a>
    <li><a href="#ref-for-contain-constraint①">4.3.1. Default Sizing Algorithm</a>
    <li><a href="#ref-for-contain-constraint②">4.3.2. Cover and Contain Constraint Sizing</a>
    <li><a href="#ref-for-contain-constraint③">4.4. Examples of CSS Object Sizing</a>
    <li><a href="#ref-for-contain-constraint④">4.5. Sizing Objects: the object-fit property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="cover-constraint">
   <b><a href="#cover-constraint">#cover-constraint</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-cover-constraint">4.3.2. Cover and Contain Constraint Sizing</a>
    <li><a href="#ref-for-cover-constraint①">4.4. Examples of CSS Object Sizing</a>
    <li><a href="#ref-for-cover-constraint②">4.5. Sizing Objects: the object-fit property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="propdef-object-fit">
   <b><a href="#propdef-object-fit">#propdef-object-fit</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-object-fit">4.4. Examples of CSS Object Sizing</a>
    <li><a href="#ref-for-propdef-object-fit①">4.5. Sizing Objects: the object-fit property</a> <a href="#ref-for-propdef-object-fit②">(2)</a> <a href="#ref-for-propdef-object-fit③">(3)</a> <a href="#ref-for-propdef-object-fit④">(4)</a>
    <li><a href="#ref-for-propdef-object-fit⑤"> Acknowledgments</a>
    <li><a href="#ref-for-propdef-object-fit⑥"> Changes Since Last Call</a> <a href="#ref-for-propdef-object-fit⑦">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-object-fit-contain">
   <b><a href="#valdef-object-fit-contain">#valdef-object-fit-contain</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-object-fit-contain">4.5. Sizing Objects: the object-fit property</a> <a href="#ref-for-valdef-object-fit-contain①">(2)</a> <a href="#ref-for-valdef-object-fit-contain②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-object-fit-none">
   <b><a href="#valdef-object-fit-none">#valdef-object-fit-none</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-object-fit-none">4.5. Sizing Objects: the object-fit property</a> <a href="#ref-for-valdef-object-fit-none①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-object-fit-scale-down">
   <b><a href="#valdef-object-fit-scale-down">#valdef-object-fit-scale-down</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-object-fit-scale-down">4.5. Sizing Objects: the object-fit property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="propdef-object-position">
   <b><a href="#propdef-object-position">#propdef-object-position</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-object-position">4.5. Sizing Objects: the object-fit property</a> <a href="#ref-for-propdef-object-position①">(2)</a>
    <li><a href="#ref-for-propdef-object-position②">4.6. Positioning Objects: the object-position property</a> <a href="#ref-for-propdef-object-position③">(2)</a>
    <li><a href="#ref-for-propdef-object-position④"> Acknowledgments</a>
    <li><a href="#ref-for-propdef-object-position⑤"> Changes Since Last Call</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="propdef-image-orientation">
   <b><a href="#propdef-image-orientation">#propdef-image-orientation</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-image-orientation①">5.1. Orienting an Image on the Page: the image-orientation property </a> <a href="#ref-for-propdef-image-orientation②">(2)</a> <a href="#ref-for-propdef-image-orientation③">(3)</a>
    <li><a href="#ref-for-propdef-image-orientation④"> Acknowledgments</a>
    <li><a href="#ref-for-propdef-image-orientation⑤"> Changes Since the 17 April 2012 Candidate Recommendation</a>
    <li><a href="#ref-for-propdef-image-orientation⑥"> Changes Since Last Call</a> <a href="#ref-for-propdef-image-orientation⑦">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-image-orientation-none">
   <b><a href="#valdef-image-orientation-none">#valdef-image-orientation-none</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-image-orientation-none">5.1. Orienting an Image on the Page: the image-orientation property </a> <a href="#ref-for-valdef-image-orientation-none①">(2)</a>
    <li><a href="#ref-for-valdef-image-orientation-none②"> Changes Since the 17 April 2012 Candidate Recommendation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-image-orientation-from-image">
   <b><a href="#valdef-image-orientation-from-image">#valdef-image-orientation-from-image</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-image-orientation-from-image">5.1. Orienting an Image on the Page: the image-orientation property </a> <a href="#ref-for-valdef-image-orientation-from-image①">(2)</a>
    <li><a href="#ref-for-valdef-image-orientation-from-image②"> Changes Since the 17 April 2012 Candidate Recommendation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="propdef-image-rendering">
   <b><a href="#propdef-image-rendering">#propdef-image-rendering</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-propdef-image-rendering">1.1. Module Interactions</a>
    <li><a href="#ref-for-propdef-image-rendering①">5.2. Determining How To Scale an Image: the image-rendering property</a> <a href="#ref-for-propdef-image-rendering②">(2)</a> <a href="#ref-for-propdef-image-rendering③">(3)</a> <a href="#ref-for-propdef-image-rendering④">(4)</a> <a href="#ref-for-propdef-image-rendering⑤">(5)</a>
    <li><a href="#ref-for-propdef-image-rendering⑥"> Changes Since the 17 April 2012 Candidate Recommendation</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-image-rendering-auto">
   <b><a href="#valdef-image-rendering-auto">#valdef-image-rendering-auto</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-image-rendering-auto">5.2. Determining How To Scale an Image: the image-rendering property</a> <a href="#ref-for-valdef-image-rendering-auto①">(2)</a> <a href="#ref-for-valdef-image-rendering-auto②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-image-rendering-smooth">
   <b><a href="#valdef-image-rendering-smooth">#valdef-image-rendering-smooth</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-image-rendering-smooth">5.2. Determining How To Scale an Image: the image-rendering property</a> <a href="#ref-for-valdef-image-rendering-smooth①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-image-rendering-high-quality">
   <b><a href="#valdef-image-rendering-high-quality">#valdef-image-rendering-high-quality</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-image-rendering-high-quality">5.2. Determining How To Scale an Image: the image-rendering property</a> <a href="#ref-for-valdef-image-rendering-high-quality①">(2)</a> <a href="#ref-for-valdef-image-rendering-high-quality②">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-image-rendering-crisp-edges">
   <b><a href="#valdef-image-rendering-crisp-edges">#valdef-image-rendering-crisp-edges</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-image-rendering-crisp-edges">5.2. Determining How To Scale an Image: the image-rendering property</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="valdef-image-rendering-pixelated">
   <b><a href="#valdef-image-rendering-pixelated">#valdef-image-rendering-pixelated</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-valdef-image-rendering-pixelated">5.2. Determining How To Scale an Image: the image-rendering property</a> <a href="#ref-for-valdef-image-rendering-pixelated①">(2)</a> <a href="#ref-for-valdef-image-rendering-pixelated②">(3)</a>
   </ul>
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